I made a song recently, but it's tough to judge how long to make it so that it's not repetitive to the listener, since it's my song and I've heard it so many times while working on it.

Of course, I know that it depends on the context it's going to be use in, and the nature of the song, among other things, but how do you decide while making a song how long it'll have to be?

Depending on how it's going to be implemented, you could try splitting it down into smaller chunks that loop - for example, if you can divide your piece into sections A, B and C you could loop A for a minute, then B for 30 seconds, back to A for 30 seconds, on to C for a minute, etc. This would only work if the piece doesn't have any overtly dramatic dynamic shifts throughout, but if you're creating looping music you should probably be avoiding them anyway.

StauntonLick makes a good suggestion - my only caveat is some devices can have issues with loading up different segments. I was working on an iPhone game where the tech placed about 1/4 of a second when finishing up segment A and loading up segment B. 1/4 of a second doesn't sound like much but it was enough to be noticeable. A talented programmer can usually smooth things out. If you happen to be on a project where the hardware/tech limitations prohibit this then I'd consider the context of the music. For example:

Title theme - probably 30 seconds as after the first few viewings the player will fly through the screen(s) quickly. I would also apply this idea to in-game menus because the player rarely spends a huge amount of time in them.

Game play - obviously the player will spend more time here. I'd recommend 30 seconds at the very, very least but hopefully something more like 60 to 90 seconds long.

Thanks,

Nate

I agree that they should be no shorter than 30 seconds, and a minute+ would be good.

However, I think it depends on the skill of the composer and the individual piece. For instance, one of my favorite game soundtracks was from the SNES game Act Raiser. Most of the tracks were pretty short, but looped extremely well. I credit this to many of the tracks having baroque influence, which facilitates good sounding repetition.

The Act Raiser track Birth of People, for instance, is what the player heard for A LOT of the game, and it's only 40 seconds or so long.

I agree that they should be no shorter than 30 seconds, and a minute+ would be good.
However, I think it depends on the skill of the composer and the individual piece.

I have to agree, some of my favorite old tunes from Secret of Mana (especially some of those reused/remix'd type tunes) and Chrono Trigger are under a minute but you barely notice since it fits the mood so well. It also depends on the type of music, very ambient background style music can get away with being shorter. Action/arcade tunes need a little more variety.

For me the iPhone limits how many MBs I'm given when we work on a game, so sometimes technical restrictions have a role in this decision too.

All of the tracks I like from video games seem to loop longer. I like Metal Man and Dr. Wily's Castle themes from Mega Man II. Those didn't seem to loop long. Pretty much all of the music from the old NES games didn't loop long and they were all hot.

Yeah i support what other guys just said, split your song into sections this has been done since NES
check this song from double dragon II and you'll notice the looping

I also was messing around with some Bit.Trip.Beat files and i found the samples used, the samples are extremely simples and in game they just sound awesome.