Stomp is a performance group that is incredibly unique: they use broomsticks, pots and pans, garbage cans, and even kitchen sinks in a mostly-percussive manner to make music. Stomp's uniqueness however stems not just from its use of non-standard instruments, but from making their music highly accessible through Performance Art.
I saw Stomp in Warner Theatre in Washington, DC last week. The performance was amazing. Especially the first ten minutes, as you get used to people actually making sense out of something you've taken for granted and never thought of as being a musical instrument. After the initial fascination with the way they make music, I started getting into the actual music itself, which is more interesting and exceeds the novelty of their instruments. That is to say, if Stomp had used regular instruments their music would have sounded equally good. However, it'd have been boring to sit through them pounding on drums---kettles and pails make for better Performance Art. Stomp did a good job at this too, mixing a lot of humour, decent amounts of choreography, and, best of all, audience participation.
To give you an idea of what their "music" sounds like: there was one piece that sounded a bit like Jerry was a Race Car Driver by Primus, complete with the short bass "solo" part that Claypool does. Another sounded a bit like Too Many Puppies (by Primus again), and one sounded like Nightflight to Venus by Boney M. That is to say to say, most of the compositions were based on short percussive riffs, which was usually built on by additional members of the troupe, with subtle variations introduced every now and then.
One of the disappointing things was that most of their songs revolved around the same sort of beat, and most of the compositions were in 4/4 time. This was presumably done so the people could relate to it, but so much more could've been accompished if they had been bolder. I also think Stomp would better served by incorporating sounds that are also melodic, instead of just percussive, and by making a bit more raw noise. Although there was a bit of that, particularly with the rubber tubes and the kitchen sinks, I would've liked to see more dissonance and cacophony. Not surprisingly, my favourite pieces by them were also the loudest ones.
From a historical standpoint, what Stomp is not original. In the mid-seventies, bands like Throbbing Gristle and (later) Einstürzende Neubaten pioneered the Industrial noise sound, which used the random sounds of everyday life (drills, chainsaws, screeches of traffic, radio static) to make "music". Even before that, John Cage had changed the shape of American music with his percussive First Construction in Metal. Stomp fits in well in such a postmodern setting. While the early Industrial bands were abrasive and non-optimistimic in their music and outlook, Stomp's noise is palatable and structured. This can get repetious and tiresome, but in the end Stomp somehow manage to make it all work.
Record labels today spend thousands of dollars on production of an album so that the right "sound" can be achieved with largely conventional instruments. Stomp causes one to stop and question "why?" While I think an album of Stomp music would be tedious, I highly recommend their live performance---there aren't many people in the world that do this.
I saw Stomp for the second time, seven years after the first time I had seen it. My review above pretty much holds, and the show hasn't changed very much. The main difference appears to be the extensive use of humour (along the lines of Blue Man Group) which marks a departure from its previous, more-serious, tone. Stomp is still purist however, and there're no real instruments being used.