If you have an Android phone, you can just hook the phone to the wifi network (infrastructure or ad-hoc) to access your shared music and play the music with the phone. The only cable will be between your phone's audio out to the TV's audio in.
You need a cable like this:http://www.newegg.com/Product/Product.aspx?Item=N82E16882678013
(I assume you mean 3.5mm stereo when you said computer in)
Not saying fruit brand, Nokia or Window phone won't work. It's just that I am not sure how to set it up.