AutoMix and crossfade

Applies to nori 0.6 on every client.

AutoMix

AutoMix (off by default) blends songs like a DJ, matching the beat. nori measures each song on the device as it arrives: its beats, bars, tempo, key and loudness. With both songs of a transition measured, it plans a mix:

Setting	Default	What it does
Longest mix	12 s	how long a mix may last (6 to 24 s)
Match the beat	on	nudges the next song’s speed so the beats line up
Biggest speed change	6 %	how far a song may be sped up or slowed down to match (2 to 8 %)
Keep the pitch	on	off lets the pitch follow the speed, up to 2 %
Swap the bass	on	the new song’s bass replaces the old one’s
Muffle the ending	on	the outgoing song fades out muffled
Echo out clashes	on	overlapping vocals end in an echo instead

Better beat detection (off by default) runs a small neural beat tracker (Beat This!) over the start and end of each song, for mixes that land on the beat more often. It needs a one-time download of about 8 MB from the model’s authors, on Wi-Fi unless you allow mobile data.

When AutoMix does not mix

The songs are not measured yet. A song is measured as it streams or downloads. Until both songs are, the transition is a plain fade.
An album plays in order. With Keep albums gapless on (the default), songs of one album that follow each other in order join without a gap, as the album was made.
The tempos are too far apart. Beyond the biggest speed change, nori does not force a beat match.
Provider songs from octo-fiesta are never measured.

Crossfade

Without AutoMix, Crossfade overlaps the end of one song with the start of the next for 2 to 12 seconds (off by default). The curve, and how long the fade in and fade out each take within it, can be set. Keep albums gapless applies here too. Fade on play and pause softens starts and stops (off, or 150 ms to 1 s).

Gapless playback needs no setting: songs that run into each other join sample for sample.