Reviewed by Ian MacDonald, in Revolution in the Head:
Like its British A-side, THIS BOY is a mood piece of little meaning. (Lennon, who wrote it, admitted there was 'nothing in the lyrics - just a sound and a harmony'.) The allusion is, again, to doo-wop (see also MISERY, YES IT IS) with special reference to the early records of Smokey Robinson and the Miracles, whose characteristic 'sobbing' climaxes are echoed in the melodramatic middle eight. With its warm major sevenths, THIS BOY adapted a traditional Fifties pop model  and became a feature of The Beatles' act during 1964 owing to the three-part close harmony which brought Lennon, McCartney, and Harrison to the microphone as a unit . But if the gentle reproach of the song's falling major second (a doo-wop hallmark) acquits it of the charge of unadulterated kitsch, the overall effect is of tweeness unrelieved by a formulaic 'teen' lyric.
Using drums only in the middle eight, the arrangement takes its slightly unsteady 12/8 pulse from a blend of pattering hi-hat and acoustic guitar, recorded with faint repeat-echo, on the left channel. This leaves the voices crammed onto the right channel, their heavy reverb leaking into the centre of the sound-picture. Lennon's solo spot in the middle eight is, moreover, brutally cut off in the edit. (An amusing excerpt from the session for this song, with Harrison and McCartney continually mixing up their 'this boy's and 'that boy's, was issued with FREE AS A BIRD.)
Posted: 15 aug 2009