Photo of the group Jefferson Airplane prior to Grace Slick's joining it.  From left-Jorma Kaukonen, Paul Kantner, Jack Casady, Marty Balin, Signe Anderson and now Spencer Dryden has replaced Skip Spence as the drummer.  The next change to the line-up would be Anderson's leaving and Grace Slick's signing on.
KRLA/Beat Publications-page 1
1966-09-10
<a rel="nofollow" class="external text" href="http://krlabeat.sakionline.net/issue/10sept66.pdf">KRLA Beat</a> page 23 The newspaper was produced for KRLA Radio in the mid 1960s.