Combining audio form many clips into a single movie

[loudmouth2332]

Hello,

I am attempting to get an effect in imovie like the one seen in this video:

http://www.youtube.com/watch?v=U-lt3vVA-4I&feature=channel_page

or, similarly, this one

http://www.youtube.com/watch?v=mHwV2JuwZls

Me and a friend are interested in combining the audio from multiple clips (one clip for each instrument) and then editing the clips of us playing together and putting the combined audio over that video but we aren't quite sure on how to get started. We figured there had to be some way of using imovie or imovie + garageband to easily get this effect. Any ideas?

Edit:
Sorry for the typo in the title. "Combining audio FROM many clips into a single movie"

 

[spinnerlys]

Like the video tracks, you have to put the different audio files into different audio tracks (I don't know how much tracks iMovie supports) and then arrange them to your liking.

Or you first arrange the audio via Garage Band, and then export a final clip into iMovie.

 

[DPA]

I see that this is your first post here at MacRumors Forums and would like to be the first to welcome you. I hope we can answer any questions or problems you may have.
If you are looking to do the effect in the second video where there are multiple frames and the audio playing just fits together then you will have to resize each frame to the same dimensions and put them together. If you want one it like in the first video you will have to do that with layering the tracks. I don't know how many tracks iMovie allows as I work in FCP. I would also suggest you take a look at the Make a Podcast part of GarageBand. This allows you to have your video shown in the GarageBand window while you can work with audio tracks natively in GarageBand. There are tutorials on how to use this feature here and here.
Please feel free to post here or PM me if this didn't answer you question. Also, don't hesitate to start a new thread if you have a question not relating to this you can also "revive" an old thread if you have a question that has been covered in a previous thread. You can also PM me with any questions or problems you may have.

Regards,
David