Rap

[Seshat]

Try telling professional symphonic percussionists, or symphonic players of the bass instruments (double bass, tuba, baritone saxophone, etc) that their 'noise' isn't 'music' unless the melody or harmony instruments are playing as well. And be prepared to have drumsticks in uncomfortable places.

[DarthRetard]

Well, technically speaking, if you pulled out just let's say, a french horn piece out of Gustav Holst's Planet's Suite, and you played JUST the french horn part from Mars, Bringer of War, you wouldn't have anything but a march beat, to be honest. Do the same with a tuba part from any of Sousa's identical sounding marches, and you have the exact same thing.

The thing you'll notice however, is even a rhythmic beat CAN be musical, and it will still make you want to march/dance/raindance/oogaboogabooga/twist/whatever.

Take Symphonic Dance No. 3, on which In high school I volunteered to cover the bass drum part. It was all triplets, to be honest, I memorized it in a day. Was it musical? No, it was rhythmic. However, in the case of rap, you may think this applies when it only has a beat and the vocals. I would argue that the vocals, if in a rhythmic pattern, can be applied as the melodic line, over the bass beat, which provides tempo, mood and style.

[Seshat]

True enough. Or for a more modern example, listen to the theme song for "Hogan's Heroes". There are a lot of bits of that where an instrument plays only a few notes for a second or so.

I played that in school band. My sheet music for that looked awful: four notes here, two notes there, five notes in another place, all apparently totally random. Not music, individually. But together with the rest of the band, it was the "Hogan's Heroes" theme song.

[Gawdzillers]

I just want to point something out here:
I believe "rap" is better used as a definition for the vocal style, not the musical genre itself (which should be referred to as "hip-hop").

Zack of Rage Against The Machine uses rapping, but RatM certainly isn't a hip-hop band.
See?

[DarthRetard]

I can't say that I would exactly disagree with that distinction, except that there are some miniscule differences between rap and hip/hop. For one, rapping still has a beat behind it, and textbook or mainstream rap has a very simplistic rhythmic nature with minimal focus on timbre, mood and melody, with the melody simply being the vocal nature of the song.

I still count RatM as the exception to the rule to be 100 % honest with you.