John Ro Myung ( ; born January 24, 1967) is an American bassist and a founding member of the progressive metal group Dream Theater.
 He is one of the two longest-serving members of Dream Theater along with John Petrucci.
Stanley Clarke (born June 30, 1951) is an American bassist and founding member of Return to Forever, one of the first jazz fusion bands.
 He has composed music for films and television and has worked with musicians in many genres.
 Like Jaco Pastorius, Clarke gave the bass guitar a prominence it previously lacked.
D.D. Verni (born Carlo Verni, April 12, 1961) is an American bassist, songwriter, and producer, best known as the founding member, bassist and songwriter of the band Overkill.
 Overkill released their first record in 1985 and with their contemporaries (Metallica, Slayer, Megadeth, Anthrax) helped define a new genre of music, "thrash metal".
 Overkill have released 18 full-length albums as well as two live albums and EPs, and several DVDs.
 They have done thousands of shows for millions of fans and toured extensively.
 They have appeared in many major music publications and have sold millions of records worldwide.
 Verni's signature bass sound is regarded as one of the most definable in heavy metal.
Michael Joseph "Mikey" Hachey (born January 29, 1985) is an American bassist, best known as a former member of the third-wave ska band, Suburban Legends.
 He joined the band in November 2004, replacing Chris Maurer on bass guitar, after his friend Derek Lee Rock (the drummer of Suburban Legends) offered him an audition to play bass for his "little ol' band" called Suburban Legends.
 Before Suburban Legends, Mike played bass in a band called Perilous, which also featured Ashley Hittesdorf (also known as Ashley Costello), vocalist from New Years Day, as a member.
 Hachey left Suburban Legends in 2010, and is a regular collaborator with artists such as Dallas Kruse and Justin Grennan and is the in-house bassist for ZionStudios in CA.
 Though no longer a member of the band, Hachey recorded bass on most of the tracks for Suburban Legends' 2012 album, "Day Job", and is credited as an additional musician on the album.
Hiro Yamamoto (山本 紘 , Yamamoto Hiro , born April 13, 1961) is an American bassist who was a founding member of grunge band Soundgarden, along with Kim Thayil and Chris Cornell in 1984.
 He left the band in 1989, and two years later, he started the independent rock band Truly together with Screaming Trees drummer Mark Pickerel and Robert Roth from The Storybook Krooks.
Rob De Luca is an American bassist, vocalist, songwriter and producer.
 De Luca is best known for playing in UFO, the Sebastian Bach band, as a founding member of Spread Eagle and as the vocalist/bassist for OF EARTH.
Gabriel Paul Katz is an American bassist and founding member of the noise rock band Blind Idiot God.
 He performed with the band since its formation, recording three studio albums with them between 1987 and 1992.
 He also assisted bandmate Andy Hawkins in the recording of his Drone music project "Halo", released as Azonic in 1994.
Kenny Gradney, a native of Baton Rouge , is an American bassist and songwriter, best known as a member of the band Little Feat.
 He joined after their second album, replacing founding bassist Roy Estrada in 1972.
 Gradney has remained their bassist ever since
Jeff Caxide is an American bassist, best known for his time with post-metal band Isis, of which he was a founding member and present until its dissolution in 2010.
 He was also a founding member of Red Sparowes, but left after the release of their first full-length.
 He also contributed to side-project Spylacopa.
 Prior to his time in Isis, he was a touring member of the Boston metalcore band 454 Big Block.
 He also helped found Connecticut-based metalcore band Cable, for whom he played bass.
 His stay with the band as a musician was brief, but he did return in order to produce 1999's "Gutter Queen".
The Mothership Returns is a two CD set and one DVD by the fusion band Return to Forever.
 Released 18 June 2012 by Eagle Rock Entertainment, the double CD set documents the music performed during the 2011 tour.
 Return To Forever was expanded for this tour to quintet and featured keyboardist Chick Corea, bassist Stanley Clarke, drummer Lenny White, guitarist Frank Gambale and violinist Jean-Luc Ponty.
 The album peaked #6 in the 2012 and 2013 Jazz Album charts.

Question: When was the American bassist and founding member of Return to Forever born who was a bassist in The Mothership Returns?
Answer: June 30, 1951