What else can I do to free up memory?

I really wanna get iOS7 on my iPhone 4, last week when it came out I only had about 35 mb left of memory (8gb phone) & over the week I deleted almost all my apps & over 900 contacts but I still don't have enough memory as its at 1.2 free right now! There's nothing else I can think of to free up memory & I'm not gonna delete any songs. Right nowhere usage is: 3.2 gb music, 287 mb Instagram, 167 mb Facebook, & 28.7 mb photos

Some app can free up your iPhone space and transfer your music to the mac.
Such as http://www.fireebok.com/ilike.html

If it works, can you give me the best answer?