This Is It was a popular song title by many artists,
as shown on this song title list,
with most This Is It titles being different songs.
While all these songs were popular, only one made the top 20.
In 1980, Kenny Loggins hit
He came back in 1993 with a popular live version. Similar song title If This Is It,
also listed here, was a
number 4 pop
number 3 rock
tune for Huey Lewis And The News.
Note that the group First Class that made song This Is It was a soul vocal group,
and not The First Class that hit
with Beach Baby.