so is this guy part of the "Hire a Idiot Program" ?

Only a true muppet would even argue those points - hope you punched him in the face , hard ...

There's a very easy way to prove that drums are a musical instrument...

Tie your friend up and beat him down with the ass end of a drumstick until he agrees. Chances are, he'll start hearing some musical notes in the stick-to-bone percussions.

Who voted 'no'?

To put it simply, if a drum is not an instrument, then by the same rule, a piano is not an instrument. Both are percussive.

John Cage would stick his foot so far up this guy's arse he'd be tasting liver spots for months.

Of course its a musical intrument..... This is a very silly question.....

his friend

What? A piano can actually produce notes, drums are strictly used to keep rhythm, unless we're talking about a steel pan drum. Anyway the piano and the drum are two entirely different instruments all together.

they both use percussion though, and a kick drum has the widest range of frequencies of any instrumental type. drums DO make different notes. think of a djembe, where you tap/how hard etc makes different notes; it's capable of creating different frequencies even though it's a percussive instrument.

I think his point was that they're both part of the percussion family, and since the OP's idiot friend was claiming that percussion instruments are not musical instruments, that would mean pianos are not musical instruments. From wikipedia: