▁the ▁music ▁of ▁The ▁Beat les . ▁As ▁well ▁as ▁recording ▁their ▁own ▁material , ▁Os ▁Mut antes ▁collabor ated ▁with ▁other ▁key ▁figures ▁in ▁the ▁bur geon ing ▁Trop ical ist ▁movement , ▁including ▁singer - song writer ▁Gil berto ▁Gil , ▁whom ▁they ▁back ed ▁on ▁Gil ' s ▁second ▁LP . ▁ ▁The ▁musical ▁manif esto ▁of ▁the ▁Trop ical ist ▁movement ▁was ▁the ▁land mark ▁ 1 9 6 8 ▁collabor ative ▁LP ▁Trop ic ál ia : ▁ou ▁Pan is ▁et ▁Circ en cis ▁(" T rop ical ia : ▁or ▁B read ▁and ▁Circ uses ") ▁which ▁brought ▁together ▁the ▁tal ents ▁of ▁Os ▁Mut antes , ▁Gil berto ▁Gil , ▁Ca et ano ▁Vel oso , ▁Tom ▁Z é ▁and ▁Gal ▁Costa , ▁with ▁arrang ements ▁by ▁avant - gar de ▁composer - arr anger ▁Roger io ▁Du pr at ▁( who ▁had ▁studied ▁with ▁Pierre ▁Bou lez ) ▁and ▁lyr ical ▁contributions ▁from ▁poet ▁Tor qu ato ▁N eto . ▁The ▁album ' s ▁group ▁cover ▁photograph ▁dep icted ▁the ▁collect ive ▁holding ▁a ▁variety ▁of ▁objects ▁and ▁images , ▁in ▁a ▁deliber ate ▁reference ▁to ▁the ▁cover ▁of ▁The ▁Beat les ' ▁S gt . ▁Pe pper ' s ▁L on ely ▁He arts ▁Club ▁Band . ▁The ▁collect ive ▁also ▁performed ▁a ▁number ▁of ▁concert ▁" h appen ings " ▁which ▁were ▁intended ▁to ▁both ▁involve ▁and ▁prov oke ▁aud ien ces , ▁and ▁these ▁reported ly ▁had ▁a ▁similar ▁effect ▁on ▁Brazil