Yes

Yes was formed in 1968 by vocalist Jon Anderson and bassist Chris Squire. Anderson was a member of The Warriors with his brother Tony, and had performed on singles under the pseudonym Hans Christian. Squire was part of The Syn, and spent time to develop his bass-playing technique following the band's split in 1967. He formed Mabel Greer's Toyshop in January 1968 that consisted of singer and guitarist Clive Bailey, drummer Bob Hagger and former Syn guitarist Peter Banks.

They played at The Marquee in Soho where Jack Barrie, owner of the nearby La Chasse club, witnessed the band playing. "There was nothing outstanding about them...the musicianship...was very good but it was obvious they weren't going anywhere". Barrie introduced Squire to Anderson at La Chasse, where they found common interest in bands such as Simon & Garfunkel and harmony singing. They went to Squire's house that evening and wrote "Sweetness", which appears on the first Yes album. Banks soon left Mabel Greer to join Neat Change, but Squire invited him back into a reformed group following the departure of Bailey and the addition of Anderson on lead vocals. Hagger was replaced by Bill Bruford, a jazz aficionado of blues revivalists Savoy Brown who placed an advertisement Melody Maker.

Bruford first met the band on 7 June 1968 and performed that day at the Rachel McMillan College in Deptford.Classically-trained organist and pianist Tony Kaye, who had been in Johnny Taylor's Star Combo and The Federals, was the fifth and final member to join. With the new line-up complete, Mabel Greer's Toyshop was renamed Yes at the suggestion of Banks.They rehearsed at a basement in Shaftesbury Avenue between 10 June and 9 July.
The band played their first show as Yes on 4 August 1968 at the East Mersea Youth Camp in Essex. Their set was formed of cover versions of other band's songs including those by The Beatles, The 5th Dimension and Traffic. "What covers they were, given the full Yes treatment! We didn't just rearrange a song – we celebrated it with much enthusiasm", said Banks. On 16 September, Yes performed at Blaise's Club in London as a substitute for Sly & the Family Stone, who failed to turn up. They were well-received by the audience, including host Roy Flynn, who became the band's manager that night. Spots at The Marquee soon turned into a residency, but Bruford decided to leave Yes in September to study at Leeds University.

He was replaced by Tony O'Reily of The Koobas, who struggled to perform on-stage. Anderson and Squire pleaded for Bruford to come back, who after being refused a year of sabbatical leave, returned for the band's supporting performance at the Royal Albert Hall for Cream at their farewell concert on 26 November 1968.

Chris Squire with Yes in 1977.
Yes' eponymous debut album was released on 25 July 1969 on Atlantic Records. Tracks included covers of "Every Little Thing" by The Beatles and "I See You" by The Byrds, as well as their original material. Lester Bangs gave a favourable review in Rolling Stone, where he described the band as promising and complimented the album's "sense of style, taste, and subtlety". Melody Maker columnist Tony Wilson selected Yes and Led Zeppelin as the two bands "Most Likely to Succeed", as he states on the record's liner notes. Yes released their second album, Time and a Word, on 24 July 1970. It features a 30-piece orchestra with band-composed material and two cover songs – "Everydays" by Buffalo Springfield and "No Opportunity Necessary, No Experience Needed" by Richie Havens. Banks, who had been particularly dissatisfied with using the orchestra on the record and the sacking of Flynn earlier in the year, left the group before the album's release on 2 May. His replacement was Tomorrow guitarist Steve Howe, who was included in the front cover photo of the American issue of Time and a Word, despite not having played on it. The album reached number 45 on the UK Albums Chart.
The Yes Album was the band's third album released on 19 February 1971. It was the first to solely feature original compositions, which the band wrote and rehearsed in a rented farmhouse in Devon. Howe quickly established himself as an integral part of the Yes sound, and played a wider variety of guitar instruments including the Spanish vihuela. The Yes Album also united the group with their long-serving producer and engineer Eddie Offord. According to Offord, the recording sessions lasted for 12 hours or more. Each track was assembled from small sections, typically 30 seconds to one minute in length, which he pieced together to form a complete track. Only after the final mix of each track would the band then learn to play the song right through for live performances. The Yes Album peaked at number 4 in the UK and number 40 on the US Billboard 200 charts.
In 1971, Kaye was asked to leave Yes. The decision was made after friction arose between Howe and himself, and his reported reluctance to play electronic keyboards such as the Mellotron and the Minimoog synthesiser. He went on to rejoin the band in 1983, 1990 and 1993. Kaye was replaced by Rick Wakeman, another classically trained player who left Strawbs and was already a noted studio musician, with credits including T. Rex, David Bowie and Cat Stevens.He embraced the use of the Minimoog and Mellotron, which gave Yes the orchestral and choral textures that their new compositions demanded.