Orra Key Pro User Manual

Orra Key Pro listens to whatever plays through its track and names the key and the scale: G minor, C Dorian, F Lydian. With it come the relative key, the codes DJ software uses, a MATCH percentage that says how sure it is, the next most likely keys, and the tuning in cents.

Then it puts the key to work, in three places:

• The chords of the key. Eleven tiles, built from the detected scale in seven chord types and six voicings. Click one to hear it, drag it into your DAW as a MIDI clip.
• The PROGRESSION strip. While your DAW plays a loop, Orra Key Pro hears its chords bar by bar, names famous progressions when it hears one, and lets you drag a chord or the whole progression into your DAW as MIDI.
• MATCHMAKER. Point it at your sample folders. It reads the key, tempo, chords and scale of every file and shows which ones fit your song, chord by chord. It previews them in time and in your key, and drags them into your project as you hear them.

Orra Key Pro never changes the audio on its track. It passes straight through with no latency; the only sound the plugin adds is the chord preview when you click a chord, and the sample preview from Matchmaker.

The manual runs front to back: the first chapters cover detection and the chords, then the progression strip, transposition, and four chapters on Matchmaker.

The window is a moss-green brushed-metal plate in five rows. Hover over anything for a tooltip.

The key card, top to bottom.

A steady readout

Once the key has settled, a different answer only takes over after it has held for 6 seconds of tonal audio, so near ties (a key and its relative, or keys a fifth apart) do not swap back and forth while the song plays. A fresh start, CLEAR or a reopened session shows the answer at once.

How Orra Key Pro listens

It measures how much of each of the twelve notes it hears (roughly 30 Hz to 2.5 kHz, tuning corrected), scores all 24 keys against that balance, then reads the scale from the notes that set that key's scales apart. Clicking tiles never changes the key.

Two loops can share a home note and a minor 3rd and still sound different: one plays the 6th a half step higher, the other the 7th. Those are scales (or modes). Orra Key Pro reads the scale on top of the key, from those deciding notes, and builds the chords, the gold notes and Matchmaker's colors from it.

Detected

The scale appears once the key has settled, and a new reading takes over after it has held for another few seconds. It needs the deciding note: a loop that never plays its 6th cannot tell Dorian from natural minor, and stays plain. A loop that uses both versions of a note (minor with both bVII and V, say) also stays plain; the borrowed chords already describe it. The key itself (the home note, major or minor, the codes) is never changed by the scale.

The SCALE menu

At the left of the chords card. Auto: Dorian (or Auto: Natural minor, Auto: Major) shows the reading; below it, the scales that suit the key in use. Pick one to use it instead: AUTO in the header lights, and clicking AUTO puts back both the detected key and the detected scale. A picked scale also applies to the MATCH TO key when it suits it; picking a key on the wheel that the scale does not suit (Lydian on a minor key) returns SCALE to Auto.

What follows the scale

The key readout, the gold bars in NOTES HEARD, the seven IN THE KEY tiles (with numerals against the scale's own notes: in D Dorian, i ii III IV v vi° VII), the four BORROWED COLOR tiles, the progression strip's numerals, MIDI clip names, the share card, and in Matchmaker the chord colors, the ranking and IN KEY. The key wheel, the DJ codes and the transpose strip stay the key's.

The key wheel lays out all 24 keys so that neighbors are musically close. It is the same numbering DJs use for harmonic mixing, and a fast way to pick a key by hand.

Picking a key

Click any key on the wheel to use it. The key card says MANUAL KEY; the chords, the NOTES HEARD colors, the transpose strip and Matchmaker follow your choice; and AUTO lights. Use this when you know better, to work in the relative key, or with no audio at all, to explore the chords of any key. Clicking an ALSO LIKELY chip does the same. The analysis keeps listening underneath: the key card shows "Detected: ... (AUTO goes back)". Click AUTO to go back to the detected key and scale.

NOTES HEARD

Twelve bars, C to B. Each bar's height is relative to the loudest note, and the percentage above it is that note's share of everything heard. Gold bars are notes of the scale in use (the detected or picked scale); the rest are gray. The keyboard strip below marks the scale notes in gold, and the home note is printed in bold. Note names follow NOTATION; a scale's notes take one letter each (A harmonic minor has a G#, not an Ab).

NOTES HEARD always shows the audio as it plays, not the transposed view. A tall gray bar is worth a look: a borrowed chord, a bent blue note, or a sign that another key fits nearly as well (check ALSO LIKELY).

Eleven tiles for the key and scale in use: seven gold tiles IN THE KEY and four violet tiles of BORROWED COLOR, under a title like CHORDS IN C DORIAN (plus (SAMPLE +2) with a transpose cell selected).

Reading a tile

At the top, the Roman numeral: the chord's step in the scale. Upper case is major, lower case minor, ° diminished, ø half-diminished, + augmented; extensions add their number or name (V7, Imaj7, IVsus4). Below it, the chord name and the notes it plays, low to high, spelled the way the chord is written: D7 reads D F# A C, never D Gb A C. The three short lines at the bottom are the drag grip.

Click to hear, drag into your DAW

• Click and hold a tile to hear the chord on a soft electric-piano voice. It sustains while you hold and rings out when you let go; the tile glows with the sound.
• Drag a tile (hold and move a few pixels) and it becomes a MIDI clip: drop it on a track in your DAW.

In the key

The seven chords built by stacking thirds on each step of the scale. Major: I, ii, iii, IV, V, vi, vii°. Natural minor: i, ii°, III, iv, v, VI, VII. Every other scale gives its own seven, named against its own notes.

Borrowed color

Four chords from outside the scale that producers reach for all the time. Each comes from a scale one or two notes away, so it sounds like a change of light rather than a wrong note.

A borrowed chord keeps its own accidental (bVI in G major is Eb, not D#) and is extended within the scale it comes from (V7 in A minor is E7: E G# B D).

The controls along the top of the chords card shape what you hear and what you drag, from the tiles and from the progression strip.

What lands in your DAW

• A standard MIDI file with one track, every note at velocity 100, with the voicing and register you chose. A tile's clip holds the chord for LENGTH; a progression block holds it for its own length.
• The clip carries the session's tempo and time signature (120 BPM in 4/4 if the host reports none).
• The file is named after the chord (Am7.mid, C#m.mid), so most DAWs name the clip after it too. Drop it on an instrument track. The files are written to a temporary folder Orra Key Pro tidies after ten minutes.

With VOICING on Smooth, drag I, V, vi and IV one after another: each takes the inversion closest to the middle of the register, so the voices move by small steps without editing.

Loop a region in your DAW and press play. Orra Key Pro follows your session's bars and beats, hears which chord sounds on each beat, finds how long the loop is, and lays the chords out on its bars. Every pass of the loop sharpens the answer.

Reading it

• The title gives the loop length (1, 2, 4 or 8 bars) and, when the chords make one, the name of a famous progression: 4-BAR LOOP | THE AXIS PROGRESSION (I-V-vi-IV).
• Each block is a chord, as long as it lasts, with its numeral in the key and scale in use. A chord changes where new notes start, so a pushed chord (struck on beat 4) lands where it was played, and a fading chord's tail is not read as a new chord.
• Chord types heard: major, minor, diminished, 7, maj7, m7 and m7b5. Richer chords (9ths, sus, add9) read as the nearest of these.
• The ruler under the blocks counts the bars.

Hear it, drag it

• Click a block to hear that chord as it was heard (Cm7 stays Cm7), voiced with VOICING and REGISTER from the chords card.
• Drag a block into your DAW: a MIDI clip of that chord, exactly as long as the block.
• DRAG ALL: the whole progression as one MIDI clip, exactly loop-length, voiced to flow from chord to chord. Loop it in your DAW and it lines up with the sample.

FAMOUS

Classic progressions in your key, ready to hear and drag: the Axis progression (I-V-vi-IV), doo-wop, the Royal Road, Pachelbel, three-chord, the Mario cadence, Creep, the plagal and Mixolydian vamps, pop minor, the Andalusian cadence, epic minor, the Aeolian descent, the harmonic minor cadence, the minor lift, and the Dorian, Phrygian and minor plagal vamps, built with TYPE, VOICING and REGISTER. A progression written for the other mode moves to the relative key, so it uses the same notes. DETECTED goes back to what was heard.

SHARE

Click SHARE to save a card of what Orra Key Pro found (key and scale, codes, MATCH, tuning, the notes, the progression and its famous name) as a 1080 × 1350 image, the shape of a portrait post. Or drag the SHARE handle straight into Discord, a browser or a folder.

The transpose card answers two questions: what key will this sample be in if I pitch it, and how far do I pitch it to fit my song? The transpose card itself never pitches the audio: use your DAW's or sampler's transpose control with the numbers shown here. (Matchmaker's IN KEY does pitch its previews; see Matchmaker: Listening.)

The transpose strip

Thirteen cells, from −6 to +6 semitones, with AS IS in the middle. Each cell shows the shift, the key the sample lands in, and that key's wheel code. Click a cell to see that key's chords: the chords card switches to it and its title says, for example, (SAMPLE +2); the wheel outlines that key in white. Pitch the sample by the same amount and drag chords that already fit it. Click the cell again to go back to AS IS.

MATCH TO

Choose your project's key in the MATCH TO menu (each entry shows its wheel code, for example Bb minor (3A); None turns it off). Then:

• The cell whose key is your project key, or its relative, fills gold: that is the shift that fits.
• Cells that land on a neighboring key (one step around the wheel, same ring) are outlined in gold.
• The line beside TRANSPOSE spells it out: "Shift +2 (or -10) to sit in C major". Both moves reach the same key; the smaller one usually keeps the sample closer to its original character. With no shift needed it says "Already in ..." or "Already fits ..." (as its relative).
• A blue dot marks the MATCH TO key on the wheel, and Matchmaker ranks your library against it.
• A scale picked in SCALE applies to the MATCH TO key too, when it suits it (Dorian on a minor key). When a scale is involved, the line compares notes: "Shift +2 to sit in D Dorian (same notes)", or "Closest: shift +3 (1 note differs from ...)".

Why the relative counts

A minor sample can sit in a major song, and the other way round, as long as the notes agree. An A minor loop fits a C major song as is: the same notes, the same chords. So Orra Key Pro keeps the sample's own mode and aims for the project key's relative when the modes differ. A G minor loop in a C major song: Shift +2, to A minor, C major's relative.

Matchmaker reads every sample in your folders (its key, tempo, chords and scale) and shows which ones fit your song, chord by chord. Click MATCHMAKER in the header to open it over the window; click it again, or the ×, to close it.

Your song's key

Matchmaker ranks against your MATCH TO key when one is set, otherwise against the key in use (detected or picked) and its scale. The line at the top says so: "Ranked against C Dorian (5A)", or "Moved into ..." with IN KEY on. Before there is a key it says "Pick a key (MATCH TO) or play your song".

Adding folders

• Click ADD FOLDER, or drop folders from Finder or Explorer onto Matchmaker. Add as many as you like; subfolders are included. Your sample folders work well.
• Each folder appears as a chip. Click a chip to show only that folder (click again for all). The × removes it from the list; nothing on disk is touched. When there are more than fit, a chip opens the full list.
• The list belongs to you, not the project: every Orra Key Pro, in every project and every DAW, shares it.

The first scan

The first time Matchmaker opens in a DAW session it reads the folders, and the status at the right counts up: "scanning 1,200 / 4,228". You can browse while it runs. For each file it reads:

• The key, from the first 45 seconds, the same way as the plugin's own detection. A key in the file name (Loop_Dmin, F#m, Bb_major) is taken as the producer's word.
• The tempo, from the file's loop information (ACID or Apple Loops), then a BPM in its name, then a length of whole bars.
• The chords, for files with a tempo, played through the same chord tracker as the progression strip.
• The scale, and whether it sounds like drums (used when the name says nothing).

Everything is kept in a cache, so the next open is quick: only files that are new or changed are read. Files longer than 10 minutes (songs, stems) are listed as "not a sample". Up to 20,000 files are listed.

New samples

Matchmaker looks for samples you have added, changed or deleted each time it opens and when you come back to your DAW from Finder or Explorer; only those are read. REFRESH, at the right of the folders, looks right away.

FITS, CLOSE, ALL

FITS: what fits as it is (or once moved, with IN KEY). CLOSE adds what mostly fits, a neighboring key or a small shift. ALL: every file. The best fits come first.

Judged by its chords

A sample whose chords say which key they are in (clear chords, three or more different ones) is judged chord by chord against your key and scale:

• Green: every note of the chord is in your scale. A plain minor key also allows its raised 7th, so V and vii° fit.
• Yellow: one of the BORROWED COLOR chords for your key and scale, or only the chord's 7th is outside it.
• Red: it clashes.

The share of the loop that fits decides the row: FITS from 85 % (every chord green, or one borrowed color among four), CLOSE from 60 %, CLASH below that.

Judged by its key

Everything else is judged by its key (the name's, else what was heard): one-shots, drum loops, files without a tempo, and lines and one- or two-chord loops, which fit too many keys to say. The FIT column then says:

Click a row to open its waveform. Click ▶, or double-click the row, to hear it; again to stop. A preview plays through this track's output and never changes the key analysis. Rows you have heard turn a little dimmer.

The waveform strip

At the bottom, for the selected row: the name, then what is known (120 BPM (from the file name) | 4-bar chord loop | moved +2 (IN KEY) | 4 of 4 chords fit C minor), and over the waveform one block per chord, named as it will sound and colored like the FIT column (FITS THE KEY, BORROWED COLOR, CLASHES). A bass line, lead or vocal shows its notes instead of chords. Click a chord to hear the sample from there.

Stars and history

Click the ☆ on a row to star it; find your stars with FILTERS > FAVORITES or "is:fav". Rows you have heard turn dimmer and can be filtered too (NOT HEARD, HEARD). Both are kept in every project; the history holds the newest 5,000 files, and CLEAR HISTORY in FILTERS forgets it. Searches and filters start fresh with each session.

Type in the search box and the list narrows as you type; the space bar types a space here, it does not start your DAW. Return or APPLY keeps the search as a chip, ready for the next one; Esc clears the box.

How words match

• Whole words: the start of a word (drum finds Drums and DrumLoop), or the end of one with four letters or more (loop finds DrumLoop); hat finds HiHat. A word never matches inside another: sub does not find "Subliminal". Spellings meet: lofi finds Lo-Fi, hiphop finds Hip_Hop, dnb finds Drum & Bass.
• "No" counts: a loop named no_kick or without vocals is not found by kick or vocal.
• Folders: a category folder (Drum_Loops, One_Shots/Kicks) counts like the name; a pack name counts for styles (house, trap, lofi), not instruments.
• drums, vocals, bass also find what the plugin knows is that type, named or not.
• When the word is not in the name, the row says where it was found: "in: Drum_Loops", "pack: Redline Tech House", "drums", "read as Dorian".

Chips and FILTERS

Under the folders, a row of chips shows what narrows the list: your applied searches and every FILTERS value. A sample must match every chip. The × removes one, and CLEAR ALL removes them all. FILTERS opens a panel: TYPE (chords, melody, bass, drums, vocals, fx), FORM (loops, one-shots), TEMPO (near my tempo, within 8 %, half and double time counted, or a range), LENGTH, SHOW (favorites, not heard, heard) and FOLDER. Types come from the name and the chords, and for a name that says nothing, from the sound: drums are recognized by ear. SORT: best fit, name, BPM, length, newest or key-wheel order.

Drag a sample

Drag a row into your DAW. With RENDER on, you get the sample as you hear it: in your key and at your tempo (with IN KEY and STRETCH), exactly its bars long, as a new file with RENDER's settings. A sample that is not moved and needs no change comes as the original file. Hold Option (Alt on Windows) as you start the drag for the original file every time.

Drag a chord, or a run of chords

• Drag a chord out of the waveform strip: that slice of the sample, as you hear it, exactly the chord's beats, so it lines up and loops on your grid.
• Shift-drag: the chord as MIDI, moved by IN KEY and voiced like the progression strip.
• Option-drag (Alt on Windows), or with RENDER off: the slice of the original file.
• Cmd-click (Ctrl on Windows) a second chord to select the run between; drag any chord in it to drag the whole run as one slice or MIDI clip. Cmd-click an end chord to drop it.

RENDER

Files go to Music/Orra Key Pro/Matched/<pack>, named after the original with its key and BPM rewritten (OS_RJ_160_Em_Honey_Keys_1 → OS_RJ_92_Dm_Honey_Keys_1), and carry their tempo. Dragging the same thing again reuses the file. Your projects point at them, so delete them yourself.

NOTATION

Key signature (the default) spells notes the way the key signature writes them: Bb in F major, A# in B major, and a scale's notes one letter each. Every chord tone takes its proper letter (D7 is D F# A C). Sharps and Flats spell every note one way. NOTATION applies everywhere, Matchmaker included.

UI scale

75 % to 200 % in steps of 25, from the menu next to the ? key. Saved with the session; if a saved size is too big for the screen, the window steps down until it fits.

Tooltips & languages

The round ? key turns the hover tooltips on and off (on by default). Right-click it for TOOLTIP LANGUAGE: English, Dutch, Japanese, Spanish, Brazilian Portuguese, German or French. Control names such as LISTEN or MATCHMAKER stay in English, so the tips match the panel.

Saved with your session

LISTEN, NOTATION, SCALE, the chord options and TUNE, the PREVIEW level, a key picked on the wheel, the selected transpose cell, MATCH TO, the UI scale and the tooltip settings. The analysis and the heard progression are saved too: a reopened project shows its key, chords and progression without playing a note.

Matchmaker's folders, SYNC, STRETCH, IN KEY, VOL, LEVEL MATCH, RENDER, stars and history are yours rather than the project's: every Orra Key Pro on the computer shares them.

Keyboard & mouse