Ok, let's just take it as read that most girls can cum by rubbing their clits and some by just fucking themselves with something. I can also cum by just squidging my thighs together. (VERY handy for cumming in school!)
I am a chorister and organ scholar too. I won't say where for obvious reasons. I find that I love to masturbate inside the organ, and especially when I know there are other people around. During choir practices, I get to play the organ unsupervised and I cannot be seen from the knave of the church or the chancel. That means that I can be daring. I usually slip my knickers off before going up to the console and always sit on the organ bench with my bare pussy in contact with the wood. (I LOVE the thought that my organ teacher will have my pussy wetness on his trousers...he could have SO much more if he wanted). While he is downstairs working on some part or other I will start to jill off. I love that at any moment he will want me to start playing again, and that just makes me 'edge' all the more. I can usually cum three or four times during a rehearsal in church and I am sure I look flushed when I come downstairs again.
I have also 'used' an organ pipe for masturbation like someone else on here has done. I guess I have a real kinky streak in me. I am still a virgin but I would LOVE to be fucked inside the organ....(and there is one choirboy in particular,,, DAMN, I would be his first in the blink of an eye... WHEN he is old enough ...or NEARLY old enough that is). For now, there is only me, my fingers and my imagination. I am ready for sex,,,MORE than ready, but I also enjoy my masturbatory life too. Oh, I forgot, during services, I have to be robed. That means cassock, surplice and since I already hold a performance diploma, I am entitled to wear the academic hood, but I sometimes go totally naked underneath.
OK, NOW I have to jill off!