Pale crag martin to do so, it would cast doubts on their specific distinctness. There are several subspecies differing in plumage shade or size, although the differences are clinal, and races interbreed where their ranges meet. The pale crag martin of the nominate subspecies "P. o. obsoleta" is 12–13 cm (4.7–5.1 in) long with light brown upperparts, becoming paler on the lower back, and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers. It has a pale grey throat, upper breast and underwing coverts, and the rest of the underparts
A Whiter Shade of Pale in 2005, Jim Irvin of "Mojo" said that its arrival at number 1 on 8 June 1967, on the same day that the Beatles' "Sgt. Pepper's Lonely Hearts Club Band" topped the national albums chart, marked the start of the Summer of Love in Britain. According to music historian Harvey Kubernik, in the context of the Summer of Love, "A Whiter Shade of Pale" was the "one song [that] stood above all others, its Everest-like status conferred by no less than John Lennon and Paul McCartney, who were enthralled by the Chaucerian wordplay and heavenly Baroque accompaniment". Kubernik also writes