Two men in adjoining duplexes, good friends, are enchanted by the song of a bird. One buys a small harmonica and learns to play it; he keeps his neighbor awake. The neighbor buys a larger harmonica, and an arms race ensues; the instruments get larger, until it's a piano vs. a pipe organ, and then they start bringing in larger groups of friends until an entire orchestra is playing the 1812 Overture. The houses collapse from all this, atop the dueling orchestras, and on their way up to heaven, the man puts his small harmonica up for sale.
These are the kind of neighbours you'd want to fire into space! Initially they get on fine, then a chirping songbird arrives and encourages one to buy an harmonica. Unwittingly, he ends up blowing into it whilst asleep one night to the chagrin of the other and next thing we know, it's all out musical war! His neighbour buys an even bigger mouth organ then there's a violin, a double bass, a trumpet...