Now here’s a crowdsourcing strategy that makes sense. The CASH Music initiative last week released two new apps that let artists give away music to fans that help spread the word via Twitter or Facebook.

Called Tweet-for-Track and FBConnect-to-Track, the “mini-apps” allow artists to offer a free download to any fan that either forwards a Twitter link or friends the artist on Facebook.

The idea came from cellist Zoe Keating, who drafted the basic idea and reached out to CASH Music for help. The Twitter version was built in time for SXSW, which she used to promote her upcoming album “Into the Trees.”

The apps are open source, meaning artists can download them for free and build on them in any way they like. From the Cash Music blog post:

You can require the user to tweet a specific phrase, follow you or not, and the download can be sent via straight http or secured using Amazon S3. All you need is a Twitter account and a webhost that can deal with PHP.

The Facebook version came about through artist Brendan Benson. Again, from the blog:

It combines Facebook’s standard “fanbox” with a simple Facebook connect implementation that lets a visitor securely verify their fan status and claim a download. Some of the benefits of this approach are subtle. The download will work for all fans, old or new, so it builds community. Facebook automatically sends a “Soandso became a fan of…” message, so we don’t need to force the user to post a message on his or her wall — but we can ask them nicely and provide a simple link. The entire process happens on one page so it feels very light.