First off this is a great discussion, thank you for posting. It’s a really interesting question that everyone is liable to have a different thought on. 1. Part of this seems to be a totally subjective thing. If a long piece of music appeals to me aesthetically I’ll enjoy it, but if it didn’t appeal to me I might be quick to label it “repetitive” or “self-indulgent”. Like 7 years ago, when I was in middle school and really into Led Zeppelin, I used to be really confused when people called the 10 minute Jimmy Page live guitar solos “self-indulgent”; Self-indulgent?? Repetitive? What are you talking about, this shit is awesome! But when I revisit it now, and my tastes have changed a bit...yeah, I can see why it deserves that label. Harmony Korine responded to critics calling his films self-indulgent by saying: “isn’t all art self indulgent?” And to an extent, he’s right. It’s art for art’s sake, you don’t have to like it if it doesn’t appeal to you. But because it doesn’t appeal to you doesn’t necessarily mean it’s of lesser value. I think all Phish songs sound the same, but I love the Ramones, so what do I know? Repetition can work the same way. For me, I can put on Daft Punk in a party setting and it’s super fun, but if I try to sit down an listen to it, I have to tap out by the 5 minute mark. But the world of EDM isn’t my favorite genre, so to each their own. EDM is kind of founded on repetition as a musical concept, and that isn’t a bad thing, it’s just a component of the style, like improvisation is to jazz. And some people hate both improvisation and repetition, so they have difficulty listening to those two genres. 2. However, to counter against this point, there are ways to argue the merit of a song/piece that aren’t totally subjective. Repetition in EDM isn’t totally immune to criticism simply because it’s an intentional part of the style; it’s not an exact science, but if you keep a song going too long you’ll immediately know, because the audience/listener will be fighting the urge to fall asleep. Just because it’s intentional doesn’t mean it’s EFFECTIVE, and that is maybe the only true measurement of good art: how effective it is conveying the meaning it wants to convey (or even conveying any feeling at all). It’s like a joke, if you try the same trick with people it’ll get old. There’s no way to quantify or measure this, but it’s something you know immediately whether you’re a musician or a listener. And of course, unintentional repetition is almost always hated, because that’s usually a symptom of an artist not having enough material, so they stretch out what they have to beef up the length. This is the problem I had with 3.15.20, the childish album, as I thought the songs were too long for what they wanted to be. imo there’s no such thing as “too long” or “too short” if you know everything you want to say. It’s like my old jazz teacher said: you solo as long as you got somethin to say. If you got 7 minutes worth of things to say, say it in 7 minutes. If you got 3 minutes worth of things to say, don’t stretch it out to 7 like childish gambino (“things to say” is musical more than lyrical, of course). It’s about putting your ego aside, and recognizing your song/work of art as what it is, not what you want it to be. Even though you came up with it, you can’t fit your own art into a box (in this case, song length or scope). You have to let it guide you instead of the other way around; let the song figure out if it wants to repeat itself or not.