Cockles and Mussels. Five Hundred Miles. Yellow Submarine. (Anything Ringo sings is within five notes, if that).

Something a voice teacher of mine did for me which was really, really useful, was to give me familiar songs where the first two notes spanned intervals. For instance, Somewhere Over the Rainbow (an octave), and so on, 6ths, 5ths, etc, (can't remember any other tunes exactly now). Really gets that hard interval stuff into the brain (of course my brain is now a sieve, but you get the idea).

yours,

Peter T.