C Notes From a Small Island a (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

ER (the late Queen Elizabeth II), containing N (abbreviation for note) + TE (another note, this time one in the musical sol-fa scale), hence “notes”; then KEY’S (belonging to a key = a small island). Enter key on a computer keyboard, used to mark the end of a line of text; sometimes called “carriage return” after the corresponding mechanism on a mechanical typewriter.