While watching Roxy the Movie, I noticed that several members of the audience are more recognizable than the others, and that they tend to stay at their own seats throughout a show. Therefore, if you pin down their locations, you can have a reference map of the audience seats for each of the four shows. And the maps should be a visual clue to find which song in Roxy the Movie belongs to which show. So I tried to locate the positions of the audience members by brightening the image of the movie. (WARNING: Be careful with the brighness; if you increase it too much, it'll hurt your eyes.) Anyway, here's the result.
A1: Man (orange sleeves)
A2: Man (big white cap)
A3: Lana (no-sleeve dress)
A4: Man (camera)
A5: Man (blue check shirt buttoned)
A6: Woman (often open-mouthed)
Roxy the Movie / More Tracks (19:25)
Roxy the Movie / More Tracks (12:35)
B1: Man (orange check shirt)
B2: Carl
B3: Man (stripe shirt; camera)
B4: Lana (long sleeve)
B5: Man (blue check shirt)
B6: Man (afro)
B7: Woman (glasses)
B8: Woman (gray coat)
B9: Man (blue check shirt unbuttoned)
Roxy the Movie / More Tracks (16:17)
C1: Man (blue T-shirt)
C2: Carl (same as B2)
C3: Lana (long sleeve; same as B4)
C4: Sherwin Tilton (camera, dark beret)
C5: Woman (glasses; same as B7)
C6: Man (big white cap; probably same as A2)
C7: Man (white hat)
C8: Man (gray clothes)
C9: Man (white shirt; beard)
D1: Man (white shirt)
D2: Woman (white pant; often cross-legged)
D3: Woman (black dress)
D4: Man (white T-shirt with a green & yellow circle)