Answer the following question: Given the following context:  Drake began recording his debut album Five Leaves Left later in 1968, with Boyd as producer. Drake skipped lectures to travel by train to the sessions in Sound Techniques studio, London. Inspired by John Simon's production of Leonard Cohen's album Songs of Leonard Cohen, Boyd was keen that Drake's voice would be recorded in a similar close and intimate style, "with no shiny pop reverb". He sought to include a string arrangement similar to Simon's, "without overwhelming ... or sounding cheesy". To provide backing, Boyd enlisted various contacts from the London folk rock scene, including Fairport Convention guitarist Richard Thompson and Pentangle bassist Danny Thompson (no relation). To provide string arrangements, Boyd already had in mind Richard A. Hewson. Initial recordings did not go well: the sessions were irregular and rushed, taking place during studio downtime borrowed from Fairport Convention's production of their Unhalfbricking album. Tension arose as to the direction of the album: Boyd was an advocate of George Martin's approach of "using the studio as an instrument", while Drake preferred a more organic sound. Dann has observed that Drake appears "tight and anxious" on bootleg recordings from the sessions, and notes a number of Boyd's unsuccessful attempts at instrumentation. Both were unhappy with Hewson's contribution, which they felt was too mainstream for Drake's songs. Drake suggested his college friend Robert Kirby as a replacement. Though Boyd was sceptical about taking on an inexperienced amateur music student, he was impressed by Drake's uncharacteristic assertiveness, and agreed to a trial. Kirby had previously presented Drake with some arrangements for his songs. While Kirby provided most arrangements for the album, its centrepiece "River Man", which echoed the tone of Delius, was orchestrated by the veteran composer Harry Robertson. Post-production difficulties delayed the release by several months, and the album was poorly marketed and supported. In July, Melody Maker described Five...  answer the following question:  Who agreed to a trial?
Answer:
Boyd