"This Guy's in Love with You" is a hit song written by Burt Bacharach and Hal David and released by Herb Alpert in May, 1968.
Although known primarily for his trumpet playing as the leader of the Tijuana Brass, Alpert sang lead vocals on this solo recording, which was arranged by Bacharach.
An earlier recording of the song by British singer Danny Williams with different lyrics, titled "That Guy's in Love", appeared on Williams' 1968 self-titled album.
Alpert recognized in the song qualities that made it a good fit for himself as a singer and trumpet player.
The composition had a recognizable Bacharach-David feel, a spot for a signature horn solo in the bridge and in the fadeout, and it was an easy song to sing for singers like Alpert with a limited vocal range.
Alpert's filmed version of "This Guy's in Love with You" appeared on April 22, 1968 as a part of his CBS television special The Beat of the Brass.
In the film, which has a studio recording of the song as its soundtrack, Alpert can be seen walking around in various natural environments in Malibu, California (including a woodland and a beach), singing the song to his wife Sharon.
In response to numerous viewer telephone calls to the network following the broadcast, Alpert decided that the song should be released as a single recording. Alpert's commercially-released recording featured a slightly different vocal performance than the recording used as the film soundtrack in the television special.
His single reached No. 1 on the U.S. Billboard Hot 100 pop singles chart in June of that year, remaining in the top position for four weeks. It was not only Alpert's first No. 1 single, but it was also the first No. 1 single for his A&M record label, as well as the first No. 1 in the U.S. for Bacharach & David.
The song also spent ten weeks at No. 1 on the Easy Listening chart. For the single's B-side, Alpert chose "A Quiet Tear" from his first album in 1962, The Lonely Bull.