Answer by taking a quote from the following article:

Don Van Vliet (, born Don Glen Vliet; January 15, 1941 - December 17, 2010) was an American singer, songwriter, multi-instrumentalist, and visual artist best known by the stage name Captain Beefheart. He conducted a rotating ensemble called the Magic Band, with whom he released 13 studio albums between 1964 and 1982. His music blended elements of blues, free jazz, and rock with avant-garde composition, idiosyncratic rhythms, and his surrealist wordplay and wide vocal range. Known for his enigmatic persona, Beefheart frequently constructed myths about his life and was known to exercise an almost dictatorial control over his supporting musicians.

After fulfilling their deal for two singles the band presented demos to A&M during 1966 for what would become the Safe as Milk album. A&M's Jerry Moss reportedly described this new direction as "too negative" and dropped the band from the label, although still under contract. Much of the demo recording was accomplished at Art Laboe's Original Sound Studio, then with Gary Marker on the controls at Sunset Sound on 8-track. By the end of 1966 they were signed to Buddah Records and much of the demo work was transferred to 4-track, at the behest of Krasnow and Perry, in the RCA Studio in Hollywood, where the recording was finalized. Tracks that were originally laid down in the demo by Doug Moon are therefore taken up by Ry Cooder's work in the release, as Moon had departed over "musical differences" at this juncture.  Drummer John French had now joined the group and it would later (notably on Trout Mask Replica) be his patience that was required to transcribe Van Vliet's creative ideas (often expressed by whistling or banging on the piano) into musical form for the other group members. On French's departure this role was taken over by Bill Harkleroad for Lick My Decals Off, Baby.  Many of the lyrics on the Safe as Milk album were written by Van Vliet in collaboration with the writer Herb Bermann, who befriended Van Vliet after seeing him perform at a bar-gig in Lancaster in 1966. The song "Electricity" was a poem written by Bermann, who gave Van Vliet permission to adapt it to music.  Much of the Safe as Milk material was honed and arranged by the arrival of 20-year-old guitar prodigy Ry Cooder, who had been brought into the group after much pressure from Vliet. The band began recording in spring 1967, with Richard Perry cutting his teeth in his first job as producer. The album was released in September 1967. Richie Unterberger of Allmusic called the album "blues-rock gone slightly askew, with jagged, fractured rhythms, soulful, twisting vocals from Van Vliet, and more doo wop, soul, straight blues, and folk-rock influences than he would employ on his more avant garde outings."

How many copies of the album were sold?