LangBeat | Music Analysis, Stems & Song Structure
Stem Energy: Which Layers Carry a Record
A finished mix is one signal, and everything about how it was built has been folded into it. Source separation reverses enough of that to ask a useful question: at any second of this record, which instruments are actually playing?
LangBeat separates every track into six stems, vocals, drums, bass, guitar, piano and effects, and stores a loudness envelope for each one. From those envelopes it can say how much of a record each layer is present for, and which layers are not on it at all.
Presence is not volume
A stem counts as present when its own level is above a fixed threshold, and its presence figure is the share of the record where that holds. A quiet pad that plays throughout is present for the whole track; a loud fill that happens twice is present for almost none of it. The measurement describes the arrangement, not the mix balance.
This is why a stem can read as absent on a record that plainly contains guitars. If the separation could not isolate them, buried under a dense mix or processed into something the model reads as effects, LangBeat reports what it measured rather than what it assumes.
What the six stems are for
Muting the vocal stem gives an instrumental; keeping only the vocal gives an a cappella. Between those two extremes, the drums and bass tell you the groove, the guitar and piano tell you the harmony, and the effects stem collects everything that is texture rather than an instrument.
The same envelopes drive the visuals. On a track page the six stems become currents flowing down the record, so a breakdown, a moment where most of the layers stop, is visible as a place where the picture thins out.
Why six
Two-stem separation splits a record into vocals and everything else, which is enough for karaoke and nothing else. Six is the point where the answer becomes musically useful: you can see the rhythm section separately from the harmony, and you can see the vocal against both.
Measured arrangements
Presence figures below were computed from each record's own separated stems, including the layers that never appear.
THẾ GIỚI CỦA ANHTINH HÀ "SAY HI"Separated into six stems, the most present layers are piano (88% of the track), vocals (82% of the track), fx (65% of the track).
BEM NU BAIPCCSeparated into six stems, the most present layers are fx (99% of the track), vocals (89% of the track), drums (64% of the track). Bass and guitar are absent.
Ela Ké CavucadinhaGordinho Bolado & Cacau ChuuSeparated into six stems, the most present layers are piano (94% of the track), vocals (90% of the track), drums (73% of the track). Guitar is absent.
$kin by cocoaCrispy Malawi & 60 GramsSeparated into six stems, the most present layers are fx (91% of the track), vocals (85% of the track), drums (61% of the track). Guitar is absent.
Nothing's Gonna Hurt You BabyCigarettes After SexSeparated into six stems, the most present layers are bass (98% of the track), guitar (93% of the track), drums (91% of the track). Piano is absent.
Garee2a Awy - A COLORS SHOWTUL8TESeparated into six stems, the most present layers are fx (91% of the track), drums (85% of the track), vocals (75% of the track).
так похуйmadk1dSeparated into six stems, the most present layers are fx (99% of the track), vocals (91% of the track), drums (89% of the track). Guitar and piano are absent.
Waiting for the EndLINKIN PARKSeparated into six stems, the most present layers are vocals (90% of the track), fx (86% of the track), drums (85% of the track).
DeiMila KarikarituSeparated into six stems, the most present layers are fx (99% of the track), drums (87% of the track), vocals (80% of the track).
TOKADhurata Dora & DJ SnakeSeparated into six stems, the most present layers are fx (88% of the track), vocals (84% of the track), drums (79% of the track). Guitar and piano are absent.
Questions
What are the six stems?
Vocals, drums, bass, guitar, piano and effects. Every analysed track is separated into all six, and each one gets its own loudness envelope across the length of the record.
What does it mean when a stem is listed as absent?
That stem's level stayed below the presence threshold for effectively the whole track. Usually the instrument is not on the record; occasionally it is present but could not be isolated cleanly from the mix.
Can I listen to a track as an instrumental?
Yes. Muting the vocal stem leaves the instrumental, and muting everything except the vocal leaves the a cappella. Both are one control on each deck in the app.
Does separation change the audio quality?
Separation produces new audio for each layer, so a stem is not identical to the instrument as recorded. It is good enough to mix with and to measure from, which is what it is used for here.