What does the expression “Who goes to the forest, who goes for firewood” mean?

When musicians play badly, music lovers will often say: “Кто в лес, кто по дрова” (“Kto v les, kto po drova”) or “Who goes to the forest, who goes for firewood”. But, what do trees have to do with it? Famous Russian fable writer Ivan Krylov has the answer.
The author of numerous satirical poems used this expression in his fable ‘Musicians’. In the story, the main character invites his neighbor for dinner, in order to listen to some singers perform together. But, it turns out that their performance is terribly uncoordinated – one goes to the forest, one goes for firewood.
In the dictionary of Russian language, Vladimir Dal mentions the expression “who goes to the forest, who goes for firewood: who's a ruble, who's a ruble and a half”. Its meaning is the same: people seem to have a common task, but everyone is busy with something different.
An English equivalent would be: “All at sixes and sevens.”