I just got this achievement with only a bass (on expert), on the song "Because". To do it, I saved up all of the Beatlemania for the first three sections, waiting until the chorus ("Love is old, love is new"), where there is a single note Beatlemania string. I set off my full reserve a few seconds before that chorus, and from there you just furiously pump the whammy bar and hope you catch all of the sections through to the last one. It's so close on the last one that I actually had to hit the note a little early, risking missing it. I ended up having 65 seconds of Beatlemania.