Musicae
Technical

Measured, not claimed. Where a number is missing, none is given.

Built for macOS, and nothing else.

Platform

macOS15.0 or later
processorApple silicon
written inSwift, SwiftUI, AppKitnative — no web view, no cross-platform runtime
iOS companioniOS 18 or laterin development, included with the purchase
application size83 MB

Playback

losslessFLAC · ALAC · WAV · AIFF · CAF · AU44.1 to 352.8 kHz, 16 to 32 bit — each one verified by decoding
lossyMP3 · AAC (.m4a, .aac) · Opus (.opus, .oga)Opus at the 48 kHz its format defines
gaplessyes
Spatial AudiokeptMusicae asks the system path for it, so Spatialize Stereo and head tracking keep working
media keysplay, pause, skipfrom the keyboard, without taking the keys from the rest of the system

This list was produced by decoding a file of each format, not by trusting a file extension. Formats that macOS does not decode — WMA, WavPack, TTA, Monkey's Audio, DSD — do not play, and Musicae will not pretend otherwise.

Under the hood

playbackAVFoundation · CoreAudio · AudioToolbox
analysisAcceleratetempo, key, energy, loudness, spectral balance — on your machine
artworkVision · CoreImagefaces are found so artist tiles crop on the person, not on the middle
interfaceCore Animationlists and grids draw in layers, which is why scrolling holds its frame rate
librarySQLite (GRDB)one file you can copy, back up and move

Measured

reference library35,480 tracksthe numbers below come from it
grid scrollingno dropped frames in 30 s
track list, idle2–4 % CPU with music playing
similar tracks120 msa neighbour list across 35,423 fingerprints
recommendation on iPhone18 ms
artwork1.4 ms per screenfulfrom the on-disk cache
analysisevery core but oneone is left to the interface, so the app stays usable while it works
key detectionmeasured against GiantSteps and 1,861 tagged tracksthe method was chosen because it scored better on both, not because it sounded plausible

Every line here is a number someone took, in this library, on this machine — not a benchmark quoted from elsewhere.

Storage

library file1.1 GB at 35,480 tracksabout 32 KB per track, most of it artwork
your audio filesstay where they arenothing is copied into a vault
locationa package in Documentsor anywhere you put it — NAS and external drives included

Network

accountnone
offlineeverything plays, everything works
what is askeda title, an artist, an albumMusicBrainz, Discogs, Last.fm, Wikipedia — for genres, artwork, biographies; LRCLIB for lyrics
what is sentnothing about youyour library, your files and your birth year never leave the Mac
scrobblingoff until you sign inwith your own Last.fm account connected, the track playing goes there — nothing else
if a source disappearsMusicae keeps workingwith fewer pictures

More on what the app does in the overview, and on what it will not do to your files in the section on findings. Questions this page does not answer: write.