an international number 1 hit. According to author Mark Brend, the song "spawned a whole subgenre of minor-key psychedelia". The Hollies' "Bus Stop", released as a single in June, was another example of the style's growing popularity. Echard identifies the song's sitar-like guitar solo as both an authentic indicator of raga rock and a device seemingly aimed at exploiting the trend. Along with "Eight Miles High", Echard highlights the Beatles' Revolver album among the "landmark" raga rock music issued in 1966. Released in August, it included "Love You To", written by Harrison especially for sitar and tabla interplay, and "Tomorrow Never Knows", which featured heavy tambura drone, tape loops and psychedelic instrumentation. The album represented pop music's most overt incorporation of Indian instruments, musical form and philosophy up to that point, with the influence also evident in the use of vocal melisma and in the Indian-inspired guitar solos on "Taxman" and "I'm Only Sleeping". That same month, the Paul Butterfield Blues Band released the album East-West, the title track of which (originally titled "The Raga") had evolved from their live performances since February. Led by guitarist Mike Bloomfield, the 13-minute instrumental fully explored the modal improvisation introduced by McGuinn on "Eight Miles High". Bloomfield likened the Indian drone to "the sound a bee makes: a steady hum" and said that while the pattern was essentially simple, the "challenge" was in "improvis[ing] a free melody around the one basic drone". In Lavezzoli's view, Bloomfield's playing on "East-West" "opened the door to unlimited freedom of expression for all rock guitarists, from Eric Clapton and Jerry Garcia to Duane Allman and Jimi Hendrix". During the height of the subgenre's popularity that year, Indian musicians also contributed to its development. Released on the World Pacific record label in June, the Folkswingers' Raga Rock album featured Harihar Rao, a Los Angeles-based sitarist and ethnomusicologist, accompanied by jazz musicians and members of the Wrecking Crew. A September 1966 issue of Life magazine reported on the growth of the raga rock trend in association with the proliferation of psychedelic-themed shops in San Francisco and New York. Acts such as Donovan, the Moody Blues, Them, the Doors, the Pretty Things and Traffic also recorded in the raga rock style. Having been accepted as a student by Shankar in June 1966, Harrison travelled to India for intensive sitar study in September. Harrison's championing of Indian culture further popularised the