i play by ear exclusively and wouldn't know what to do with the sheet music less'n (oklahoman for unless) it included the lyrics, so my suggestion will seem unorthodox, but listen intently to the songs until you can both sing and play them in your sleep and strive to break away from the sheets with the little mouse droppings on them. unless its an orchestral score you seldom see a professional musician who is tied to sheet music...they memorize both the words and the music. so, my friend, simon, your mission, should you decide to accept it, is to learn the songs inside and out, frontward and backward until you can play them flawlessly from memory. the best musicians i've ever known were a combination of sight readers and a fabulous set of ears.

warning: (actung) this message will self-destruct in 30 seconds!

(somebody will jump in here and tell me that i have misspelled 'actung' in which event i will whip out my german poetic license, which i recently renewed, and thumb my nose at somebody.)