Your ideas are dying in your voice memos.

It locks before you've finished the pluck.

Detection is the McLeod method — a normalized square-difference function, the algorithm built for instrument pitch — running on Apple's Accelerate framework on the audio thread. The autocorrelation is hardware dot products, not a loop. It re-reads about every 23 milliseconds and locks a note in two confirming frames, on the order of fifty.

An onset detector watches for a fresh attack and drops its search lock the instant you pluck again, so a jump from low E to A, or a hammer-on, follows the new note instead of hanging on the old one. The readout is native SwiftUI — no web view spins up to draw it.

The reason most phone tuners choke, fixed.

iOS runs the mic through processing tuned for phone calls, and it scrubs everything around 80 to 110 Hz — exactly where a low E, A, and B live. That's why most tuners make you pluck a low string three times before it catches anything.

We open the mic in measurement mode, which bypasses that filter, then set the detection threshold against real device logs so a valid low pluck is never thrown out. A low E locks first try, same as the high ones.

Steady when you hold it, instant when you bend.

The detected pitch is interpolated between samples for sub-cent resolution, smoothed through a median and a 1€ filter — the adaptive filter from motion tracking — then eased onto the display at 60 frames a second. It sits still on a held note and moves the moment the pitch does. Three cents reads in tune.

Guitar, bass, ukulele, and violin by string, a full chromatic mode for anything else, and a reference A from 432 to 444.

Our own canceller, built for music.

We turned off the phone's built-in echo cancellation. It's made for phone calls, so it hears a held chord as noise and scrubs it, and your take comes back underwater.

Ours already knows the backing, because it played it. In the count-in it reads your room and speaker, then pulls the bleed out of your take and leaves what you played alone.

That's the hard case, nothing in your ears. Plug in headphones or AirPods and there's no bleed to cancel. Either way you're on the phone's mic, so the input's the same.

Bluetooth lies about timing. We correct for it.

A speaker adds a little delay. Bluetooth adds a lot, and most recorders land your part late. This one measures the real delay every take and slides it back into place.

When Bluetooth still drifts, a per-track nudge wheel slides a part a few milliseconds by ear until it sits.

This is the step before the DAW.

No mixing desk, no plugins, no automation. It's where an idea becomes a named sketch while you still care. If it earns a full production, export it and open your DAW. Most never get that far. That's the gap.

Every mode knows its own chords.

Not the usual seven. Major and all three minors, every major mode, all six modes of harmonic minor and all six of melodic minor, and an exotic shelf — Double Harmonic, Hungarian Minor, both Neapolitans. Each scale carries the triad and the seventh for all seven degrees, so the chords it hands you are right for the mode: the augmented tonic in Ionian ♯5, the ø7 in Locrian, the major-♭5 in Double Harmonic.

Spelled correctly — flat keys get flats — with proper Roman numerals (°, ø, +) and Nashville numbers. Every scale comes with what it's for: the mood, the songs that used it, the degree spelling. You get the why, not just the notes.

Play it the chord, it names it.

Identify is a true reverse lookup: hand it a set of notes and it tries each one as the root against thirteen chord types — triads, sus2 and sus4, the four common sevenths, m7♭5, dim7, m(maj7), aug(maj7) — then ranks exact matches first, simplest next. Tell it the chords you've got and it finds the key they fit.

Organized like a song, not a dictionary.

Per scale, sorted into verse, chorus, and bridge — each one a scale-degree pattern with a functional note and the records that used it, from I-V-vi-IV to the Andalusian descent. They're stored as degrees, so they land in whatever key you're working in. A starting point, not a lookup table.

The fretboard, not just a scale on it.

The five pentatonic positions with their root anchors, the blues scale with the ♭5, chord-tones-only, the modal colors (Dorian's 6, Mixolydian's ♭7, Lydian's ♯4), and the advanced moves — superimposed pentatonic up a fifth, the diagonal 3:2 run. Plus the signature shapes by their real geometry: the BB King box on the top three strings, the SRV zone fusing boxes one and two, the Hendrix major/minor-third blur. Each with a technique note, mapped to your key, in any of ten tunings from Drop D to DADGAD.