Columbia Records eventually released the "Mr. Tambourine Man" single on April 12, 1965. The full, electric rock band treatment that the Byrds and producer Terry Melcher had given the song effectively created the template for the musical subgenre of folk rock. McGuinn's melodic, jangling twelve-string Rickenbacker guitar playing—which was heavily compressed to produce an extremely bright and sustained tone—was immediately influential and has remained so to the present day. The single also featured another major characteristic of the band's sound: their clear harmony singing, which usually featured McGuinn and Clark in unison, with Crosby providing the high harmony. Additionally, Richie Unterberger has stated that the song's abstract lyrics took rock and pop songwriting to new heights; never before had such intellectual and literary wordplay been combined with rock instrumentation by a popular music group.