Always check with the band as many bands will have stage size requirements written into their performance contract or rider agreement. Many bands have a preferred stage size but are able to perform on a small stage if room doesn't allow for their preferred size.
Below are suggested minimum stage size for musical groups
Solo Performance - 4' x 8'
2 Piece Band - 8' x 12'
3 Piece Band - 12' x 16'
4 Piece Band - 12' x 20'
5 Piece Band - 16' x 20'
