If you happen to be in the same room as Bacterial Orchestra - interact with it. The complexity of the generated sound doesn’t come from the mechanism of every single cell, but from their interactions. The music is played by the organism as a whole. Listen to the orchestra, not to its members.
Every cell has a unique DNA. Only the ones that are musical fit enough survives. If the surroundings doesn’t meet up to its conditions - too noisy, too quiet or no distinct pulse - the cell dies and is reborn with a new set of DNA.
The result is a musical organism adapting to its environment, growing and evolving with neighbouring cells and spectators.