"This Guy's in Love with You" is a song written by Burt Bacharach and Hal David, and recorded by Herb Alpert. Although known primarily for his trumpet playing as the leader of the Tijuana Brass, Alpert sang lead vocals on this solo recording, arranged by Bacharach.As documented in a "Biography" cable episode featuring Bacharach, the recording originated when Alpert asked Bacharach, "Say, Burt, do you happen to have any old compositions lying around that you and Hal never recorded; maybe one I might use?" Alpert said he made it his practice to ask songwriters that particular question; often a lost "pearl" was revealed. As it happened, Bacharach recalled one, found the lyrics and score sheet, and offered it to Alpert: "Here, Herb . . . you might like this one."Alpert saw the possibilities in it for himself. 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 within Alpert's vocal range. He originally sang "This Guy's in Love with You" on a 1968 television special, The Beat of the Brass. In response to numerous viewer telephone calls following the broadcast, Alpert decided that the song should be released as a single recording, and it 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. 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," an album track from his first album in 1962, The Lonely Bull.Eleven years later Alpert became the first (and only) artist to have reached the prized No. 1 position of the Billboard Hot 100 with both a vocal performance and an instrumental performance when his instrumental, "Rise", reached the top of the hit chart.Interestingly, "This Guy's in Love with You" was succeeded at No. 1 on the Billboard Hot 100 by "Grazing In The Grass", an instrumental by Hugh Masekela. On the Billboard Easy Listening chart, Alpert's song was both preceded and succeeded at No. 1 by instrumental hits from Hugo Montenegro ("The Good, the Bad and the Ugly") and Mason Williams ("Classical Gas"), respectively.