Stem separation · split guitars

Mr History

Two live takes, both guitars pulled apart into separate tracks

This lifts the two guitars out of each live board mix as separate tracks, the way our Songsterr pipeline needs them: one clean stem per guitar, each ready to transcribe on its own. The split decision is measured on the audio, not guessed. Both takes came back the same way, two guitars panned left and right.

How the split was made

01

Demucs 6-stem

The full mix runs through htdemucs_6s, giving drums, bass, vocals, piano, other, and one isolated guitar stem.

02

Measure the pan

With centered drums and bass gone, the two guitars' left/right panning is exposed. I measure side energy and channel correlation to confirm they are really panned apart.

03

Split L / R

The guitar stem splits into Guitar L and Guitar R, the two players, plus a side signal that isolates the hard-panned difference.

The Brick

Chored · 3:22
PANNED: TWO GUITARS

The two guitars sit apart in the stereo field, so Guitar L and Guitar R are the two separate players. Correlation of 0.81 means they still share some center on unison passages, so the side signal is there for the widest separation.

0.811
L/R correlation
(lower = more separate)
−9.7 dB
side vs center
−14.4 dB
Guitar L level
−15.4 dB
Guitar R level
44.1 k
sample rate
GUITAR L

Left player

The guitar panned left, lifted out on its own.

Guitar L waveform
GUITAR R

Right player

The guitar panned right, lifted out on its own.

Guitar R waveform
SIDE (L−R)
Widest separation
MID (L+R)
Shared center
GUITAR STEM
Both, pre-split
ORIGINAL MIX
Full band

Crosstown Station

9:36
PANNED: TWO GUITARS

Same result at the longer take. Correlation 0.80 with 9.2 dB of side energy under center, so Guitar L and Guitar R are the two players here as well.

0.795
L/R correlation
(lower = more separate)
−9.2 dB
side vs center
−13.5 dB
Guitar L level
−15.0 dB
Guitar R level
44.1 k
sample rate
GUITAR L

Left player

The guitar panned left, lifted out on its own.

Crosstown Guitar L waveform
GUITAR R

Right player

The guitar panned right, lifted out on its own.

Crosstown Guitar R waveform
SIDE (L−R)
Widest separation
MID (L+R)
Shared center
GUITAR STEM
Both, pre-split
ORIGINAL MIX
Full band

Files on disk

The players above are 192k mp3 for the web. For Songsterr use the full-quality 44.1k WAV split files.

The Brick

# two split guitars + side + mid + verdict
~/Projects/_outputs/split-guitars/thebrick_split/guitar_L.wav
~/Projects/_outputs/split-guitars/thebrick_split/guitar_R.wav
~/Projects/_outputs/split-guitars/thebrick_split/guitar_side.wav
~/Projects/_outputs/split-guitars/thebrick_split/guitar_mid.wav
~/Projects/_outputs/split-guitars/thebrick_split/split_verdict.json
# all 6 demucs stems
~/Projects/_outputs/split-guitars/htdemucs_6s/Mr History The Brick - Chored/

Crosstown Station

# two split guitars + side + mid + verdict
~/Projects/_outputs/split-guitars/crosstown_split/guitar_L.wav
~/Projects/_outputs/split-guitars/crosstown_split/guitar_R.wav
~/Projects/_outputs/split-guitars/crosstown_split/guitar_side.wav
~/Projects/_outputs/split-guitars/crosstown_split/guitar_mid.wav
~/Projects/_outputs/split-guitars/crosstown_split/split_verdict.json
# all 6 demucs stems
~/Projects/_outputs/split-guitars/htdemucs_6s/9 Mr History Crosstown Station/