ðə mˈeɪnstɹiːm fˈɪfti sˈɪks θˈaʊzənd slˈæʃ ˈɛs sˈɪks θˈaʊzənd sˈɪɹiz kəmˈɛnst ɪn nˈaɪntiːnhˈʌndɹɪd sˈɪksti fˈoːɹ wɛn ðə lˈeɪbəl wʌz ɪstˈæblɪʃt baɪ bˈɑːb ʃˈæd ænd ɹˈæn ʌntˈɪl nˈaɪntiːnhˈʌndɹɪd sˈɛvənti wˈʌn ænd ɪnˈɪʃəli ɹiːˈɪʃuːd mətˈɪɹiəl fɹʌm kˈɑːmədˌoːɹ ɹˈɛkɚdz ænd tˈaɪm ɹˈɛkɚdz ɐn ˈɜːlɪɚ bˈɑːb ʃˈæd lˈeɪbəl ɪn ɐdˈɪʃən tə sˌʌm nˈuː dʒˈæz ɹᵻkˈoːɹdɪŋz, ðˈɛn sˈaʊndtɹæks, bᵻfˌoːɹ bɹˈæntʃɪŋ ˌɪntʊ sˌaɪkɪdˈɛlɪk ɹˈɑːk ɚɹˈaʊnd nˈaɪntiːnhˈʌndɹɪd sˈɪksti sˈɪks.
The Mainstream 56000/S6000 Series commenced in 1964 when the label was established by Bob Shad and ran until 1971 and initially reissued material from Commodore Records and Time Records (an earlier Bob Shad label) in addition to some new jazz recordings, then soundtracks, before branching into psychedelic rock around 1966.