Spector's strongest work was in creating hit singles. He knew many fans never listened to the B-sides of singles, and radio seldom played them, so often his B-sides would feature an instrumental jam session, without the singers credited on the record, and with titles like "Flip and Nitty". Spector also disliked albums. He called them "two hit (song)s, and ten pieces of junk". When stereo became more popular than mono in recording, Spector did not follow the trend. In later years he wore a red badge in public, with the words BACK TO MONO.