1. SOS is a musical term, meaning "same only softer".
2. I know what a sextet is, but I'd rather not say.
3. Stradivarius is an imaginary prehistoric animal.
4. Refrain means don't do it. In music, it's the part you'd better not try to sing.
5. Anyone who can read all the instrument notes at the same time gets to be the conductor.
Taken from Must Try Harder! The Very Worst Howlers by Schoolchildren. Published by Constable Robinson. www.constablerobinson.com.