Yes, INTERMEZZO is a Scrabble word!

Letter values in Scrabble US: I 1, N 1, T 1, E 1, R 1, M 3, E 1, Z 10, Z 10, O 1.

Is it a valid word?

INTERMEZZO is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a short movement coming between the major sections of a symphony
a short piece of instrumental music composed for performance between acts of a drama or opera
a brief show (music or dance etc) inserted between the sections of a longer performance

Also: entr'acte.