I've searched everywhere and can't find a version that's not this
http://us.api.mobilestreams.com/snd_stream.asp?cid=80767&type=midi
or this
http://the-op.com/media/sound.php?fmt=mid
(since they're both genuinely terrible renditions).

For reference, it's the theme playing in the background of this MP3
(http://the-op.com/media/sound.php?aid=17&fmt=mp3), but I need it
*without* the narration on top of it, pleasant through Ron Howard's
voice may be.

Hello  sa22112,

The Arrested Development theme song was composed by David Schwartz.


An MP3 copy of this song without the narration is available on David
Schwartz?s website.
http://www.davidschwartzmusic.com/home.htm

Download here:
http://www.davidschwartzmusic.com/music_main.htm

Or use the direct link below:
MP3 TV Theme - Arrested Development
http://www.davidschwartzmusic.com/music/arrested_development.mp3

 
Search terms:
"Arrested Development" theme music

I hope the information provided is helpful!

Best regards,
Bobbie7