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 that, amid the search for higher consciousness during the flower power era, the song "galvanised a congregation of disaffected youth dismissive of traditional religion but anxious to achieve spiritual salvation". In his 1981 article on the musical and societal developments of 1967, for "The History of Rock", sociomusicologist Simon Frith described "A Whiter Shade of Pale" as the year's "most distinctive single", through its combination of "white soul vocal and a Bach organ exercise" and enigmatic lyrics that "hinted at a vital secret open only to people in the right, drug-determined, state of mind". In the United States, the single