Johnny Contardo (born December 23, 1951) is a former singer with the musical group, Sha Na Na which he left in 1983. In 1978, he appeared with Sha Na Na in the movie musical "Grease" as Johnny Casino and the Gamblers. His performance of the song "Those Magic Changes" was featured in the movie and on the soundtrack for "Grease".
Johnny Contardo was not a former singer with the musical group Sha Na Na Na.
I used "not" and then similar wording to trick the system, but the musical group that I mentioned is not actually listed at all in the statement (so it's not clear whether it's true or not based on the context).