Everyone likes to sing. The use of sound has a tremendous range of possibilities and much of it can be presented online - either as streaming media or downloads.
Songs: These can be written as and when about almost anything - ideally with some Buddhist connection. They could be written in relation to the 'theme of the month' - to be used as part of the Sunday school.
Mantra: These can be traditional or you can make them up yourselves - simple or complex.
Rap: It has a bit of a dark image as a result of many commercial offerings but it is a medium with much potential. Have a look at this one . So, what words can you put to a beat?

Without doubt most of the material you produce can go on the site.
Given enough (reasonable quality) material we could compile a tape or CD. Have a look at the small sample of sounds that came through some of the events at Amaravati .
There are opportunities for collaboration - you do the words they do the music - or v.v
There can be several sound versions posted for voting - 'The Best of ...."
This could include guided meditations.
Almost anything that makes a noise could find a way to exist in relation to the Buddha's teaching ...
The first sound of your new-born cat
the sound of the wind outside your window
OK, so I scratching for ideas here to fill the page but there are many possibilities.

What can you think of ...?