Bubblegum pop (also known as bubblegum rock, bubblegum music, or simply bubblegum) is a genre of pop music whose classic period ran from 1967 to 1972. The chief characteristics of the genre are that it is pop music contrived and marketed to appeal to pre-teens, is produced in an assembly-line process, driven by producers and using faceless singers, and has an intangible, upbeat "bubblegum" sound. The songs typically have singalong choruses, seemingly childlike themes and a contrived innocence, occasionally combined with an undercurrent of sexual double entendre. They also have a catchy melody, simple chords, simple harmonies, danceable beats, and repetitive riffs or "hooks". The song lyrics often concern romantic love, but are notable for their frequent reference to sugary food, including sugar, honey, jelly and marmalade.