used in religious ceremonies, was an instrument that Harrison had enthused about after seeing Bismillah Khan perform at the Hollywood Bowl in August 1967. Also prominent on the soundtrack is the tar shehnai, a bow-played string instrument that is similar to an esraj. Other instrumentation introduced on Wonderwall Music includes the sarod, similar to a lute, and the santoor, a type of hammered dulcimer with up to 100 strings. Having used personnel from the Asian Music Circle in north London on his Beatles songs "Love You To" and "Within You Without You", in addition to his own sitar playing, Harrison decided to record part of the soundtrack in Bombay, the centre of India's film industry, in order to work with some of the country's best musicians. The Wonderwall score was Harrison's first opportunity to compose extensively for a single project. He later described how he went about preparing the music: "I had a regular wind-up stopwatch and I watched the film to 'spot-in' the music with the watch. I wrote the timings down in my book, then I'd go to [the recording studio], make up a piece, record it." As with his songs for the Beatles over this period, including "Within You Without You" and "Blue Jay Way", he composed mainly on keyboard instruments such as piano or organ, rather than guitar. In addition to the Indian pieces, Harrison wrote and arranged selections in Western musical styles. In some cases, these pieces were outlined to the musicians at the recording session by Harrison, on guitar, and they then improvised on his ideas. With other selections, he first made a demo, which the musicians followed. Harrison collaborated on much of the project with John Barham, who had studied composition under Harrison's sitar teacher, Ravi Shankar. A classically trained pianist and musical arranger, Barham annotated some of the melodies that Harrison sang to him and transcribed them onto staves. Leng describes Barham as Harrison's "fellow traveler", due to the two musicians' shared appreciation of Indian classical music. He adds that their musical compatibility made Barham a natural choice over George Martin, the Beatles' producer and orchestral arranger. Recording London, November 1967 – January 1968 The first session for the Wonderwall soundtrack took place on 22 November 1967 at EMI Studios (now Abbey Road Studios) in London. That day, Harrison recorded with a tabla player and flautists Richard Adeney and Jack Ellory, taping