Vintage guestbook from the Los Angeles–area rehearsal studio Modern Musical Services, 7.5 x 9.25, signed on both sides of the first six pages by various acts who booked the space between September 22, 1967, and July 29, 1968, including the Grateful Dead, The 5th Dimension, Del Shannon, and others. On the first page is an extremely rare set of Grateful Dead signatures, dated October 17, 1967, signed by their manager Ron 'Pigpen' McKernan, "R. C. McKernan," and the band, "Bob Weir," "Jerry Garcia," "Bill Sommers" (Bill Kreutzmann's pseudonym), and "Mickey Hart," who had signed on as the Dead's second drummer just three weeks prior; the back of the page bears signatures of their manager, "Rock R. Scully," bassist, "Phil Lesh," and sound engineer, "Robert C. Matthews." During the band's early days, the underage Kreutzmann sometimes used a fake draft card filled out with the name "Bill Sommers" to be admitted into bars for the Dead's gigs. He and Hart combined to make the Grateful Dead one of the first rock bands to feature two drummers, developing their signature sound as 'the Rhythm Devils.'
Other notable signatures include The Animals (including Eric Burdon, Danny McCulloch, John Weider, Vic Briggs), The 5th Dimension (Marilyn McCoo, Billy Davis, Jr., Lamonte McLemore, and Ronald Townson), troubled singer-songwriter Lowell George (2), Del Shannon, John Densmore and Robby Kreiger of The Doors, Tommy Boyce and Bobby Hart, jazz drummer Louie Bellson, and more. In fine condition.