Some context: Pink Floyd were an English rock band formed in London in 1965. They achieved international acclaim with their progressive and psychedelic music. Distinguished by their use of philosophical lyrics, sonic experimentation, extended compositions, and elaborate live shows, they are one of the most commercially successful and influential groups in popular music history. Pink Floyd were founded by students Syd Barrett on guitar and lead vocals, Nick Mason on drums, Roger Waters on bass and vocals, and Richard Wright on keyboards and vocals.
In December 1967, the group added guitarist David Gilmour as the fifth member of Pink Floyd. Gilmour already knew Barrett, having studied with him at Cambridge Tech in the early 1960s. The two had performed at lunchtimes together with guitars and harmonicas, and later hitch-hiked and busked their way around the south of France. In 1965, while a member of Joker's Wild, Gilmour had watched the Tea Set. Morrison's assistant, Steve O'Rourke, set Gilmour up in a room at O'Rourke's house with a salary of PS30 per week (equivalent to PS500 in 2016), and in January 1968, Blackhill Enterprises announced Gilmour as the band's newest member; the second guitarist and its fifth member, the band intending to continue with Barrett as a nonperforming songwriter. Jenner commented: "The idea was that Dave would ... cover for [Barrett's] eccentricities and when that got to be not workable, Syd was just going to write. Just to try to keep him involved". In an expression of his frustration, Barrett, who was expected to write additional hit singles to follow up "Arnold Layne" and "See Emily Play", instead introduced "Have You Got It Yet?" to the band, intentionally changing the structure on each performance so as to make the song impossible to follow and learn. In a January 1968 photo-shoot of the five-man Pink Floyd, the photographs show Barrett looking detached from the others, staring into the distance.  Working with Barrett eventually proved too difficult, and matters came to a conclusion in January while en route to a performance in Southampton when a band member asked if they should collect Barrett. According to Gilmour, the answer was "Nah, let's not bother", signalling the end of Barrett's tenure with Pink Floyd. Waters later admitted, "He was our friend, but most of the time we now wanted to strangle him". In early March 1968, Pink Floyd met with business partners Jenner and King to discuss the band's future; Barrett agreed to leave.  Jenner and King believed Barrett to be the creative genius of the band, and decided to represent him and end their relationship with Pink Floyd. Morrison then sold his business to NEMS Enterprises, and O'Rourke became the band's personal manager. Blackhill announced Barrett's departure on 6 April 1968. After Barrett's departure, the burden of lyrical composition and creative direction fell mostly on Waters. Initially, Gilmour mimed to Barrett's voice on the group's European TV appearances; however, while playing on the university circuit, they avoided Barrett songs in favour of Waters and Wright material such as "It Would Be So Nice" and "Careful with That Axe, Eugene".
Why was Barrett replaced?
A: Working with Barrett eventually proved too difficult,

Some context: Broken Social Scene is a Canadian indie rock band, a musical collective including as few as six and as many as nineteen members, formed by Kevin Drew and Brendan Canning. Most of its members play in various other groups and solo projects, mainly in the city of Toronto. These associated acts include Metric, Feist, Stars, Apostle of Hustle, Do Make Say Think, KC Accidental, Emily Haines & The Soft Skeleton, Amy Millan, and Jason Collett.
In June 2007, BSS founder Kevin Drew began recording an album which featured many members of Broken Social Scene. The album was produced by Ohad Benchetrit and Charles Spearin and was titled Broken Social Scene presents ..Spirit If.... The album was recorded throughout 2004 and 2006 in Ohad Benchetrit's house while the band was not on tour. Although billed as a solo project, most Broken Social Scene members make cameo appearances. The sound itself is Broken Social Scene's familiar mix of rough and ragged, sad and celebratory, with psychedelic swells and acoustic jangles. Also featured are Dinosaur Jr.'s J Mascis and Canadian rock icon Tom Cochrane playing and singing and handclapping along. The album was released on September 18, 2007 and a tour billed as Broken Social Scene Performs Kevin Drew's Spirit If... took place in late 2007.  The second "Broken Social Scene presents..." record, by Brendan Canning, is entitled Something for All of Us and was released on Arts & Crafts in July, 2008. Broken Social Scene also took part in the 2008 Siren Music Festival in Coney Island, Brooklyn.  On April 29, 2009, Kevin Drew and Brendan Canning guest-hosted 102.1 The Edge's program The Indie Hour to promote their concert at the Olympic Island Festival. The festival was later moved to Harbourfront Centre after a labour dispute resulted in the suspension of ferry service to the Toronto Islands.  In May 2009 Arts & Crafts, with association from Anansi Press, released This Book Is Broken written by The Grid editor Stuart Berman, who had a close personal involvement with the band. The book includes artwork, concert posters and photographs (professional and amateur) of the band. Berman includes extensive interviews with band members and related persons, arranged by subject and chronology.
what did they present
A:
In June 2007, BSS founder Kevin Drew began recording an album which featured many members of Broken Social Scene.