What is the best way of making an electric instrument??

I am making a musical instrument for a school project and i need something to adjust the volume and/or pitch, but i don't know what to use. I am only 13 so i have little resources and no money to spend so i was considering using a single wire and a guitar pickup (not actually a guitar pickup, a speaker backwards) and i want to know what the pros and cons of this method are and whether or not there is a way of making a dimmer switch. Thankyou in advance. P.S. Once i have a good idea i am going to plan it and take lots of photos and if it works i will post an Instructable. P.P.S. Everyone in my form at school is saying there making a rainmaker and guitar with elastic bands so I'm gonna really enjoy seeing there faces if this works!!! P.P.P.S. Should i have written P.S.S. and P.S.S.S etc.?

nofunclub8 years ago
p.p.p.s would be correct. P.S stand for Post Script (latin for Afterword) so p.p.s is Post Post Script... ..but don't get carried away, it could look silly!
ps.see pps pps see ppps ppps see pppps pppps see ppppps ppppps pie