Yeah, I assumed he was talking about sustain.

I've said many times, a genre has multiple things that make a genre, and that not all bands follow all of the rules. Let me see if I can do this, not that I'll be good at it:

Alternative rock's sound, to me, seems to be interchangeable between slightly fuzzy guitars (a trait from early alternative such as Sonic Youth or Pixies, who were both major influences on the indie scene), and notably sustained notes between the acoustic and electric guitars as well as the vocals occasionally. As far as the tone goes, the tone seems to be based on the lyrical content of social disconcern. However, unlike grunge and punk, alternative seems to show off a control of the emotion, using anyt and all emotion the artist expresses as a musical instrument rather than a way to relate to the audience, although he may still succeed at relating, like with OK Computer. The music itself is an emotion.

That's it. It's its own emotion. Folk rock, post punk, punk rock, genres genres based on emotion. These are lighlty influenced in the majority of modern alternative rock. Alternative Rock is a musical emotion.

Well, I got my own description for it. I think I'll use that. As far as the fuzzier alternative bands gpo, they seem to take after the early alternative before this "underground" scene had a distinct sound, so I could say to myself that's an original form of alternative rock from the 80's that helped form the more emotional sound that popularizes the common 90's and 2000's sound.

Well, that's a step up, but still not enough. "Not glam rock" just includes too much.

Grunge is a form of alternative. Just like how thrash is a form of metal.

Tpo shorten it:
Rock mostly based on sustained notes and a little emotion. If anyone asks me about early alternative rock or how Pixies and Smashing Pumpkins aren't like that, I'll tell them about how alternative rock's complications. But I think this is as close as I can currently get at a "distinct sound."

Something that doesn't exist in alternative music. The only thing that brings the genre artists together is what they aren't, since they are the ALTERNATIVE form of rock to glam.

Grunge takes after the EARLY alternative from the 80's, as well as the Seattle punk scene. Keep in mind, Sonic Youth is the early alternative form, fuzzy and against the mainstream. Nirvana's Nevermind kind of serves as a bridge between both, so IO guess that's another reason why Nevermind is so good: it has elements of both forms. It did help to ironically popularize the style. But as alternative was pioneering jangle pop (The SMiths, REM), the sound became more distinct.

And now for indie rock. That's an even hardeer cookie to crack. I suppose its stylistic origins are the same as alternative rock. Different sound back then, and that differne tsound as well as a new and more popular sound are both "indie rock."

@Frown, all I can tell you is I'm listening to Transmission by the Tea Party right now and I'm getting the exact same vibes I get from Radiohead, Audioslave, REM, Pearl Jam, and Stone Temple Pilots.

Rock music from an independent label. This one is undebatable.

Bro, alternative isn't a cohesive genre. It's like metal. You can't just say that alternative sounds like *X*. There are too many different kinds of bands and sub-genres within the genre to do that.

Indie rock is a form of alternative. Your attempts at defining a sound for alternative are downright cartoonish.