James Jamerson, the virtuosic Motown bassist, probably did more for the success of the label than anyone. There are several reasons for this, the most vital being that music is usually "polarized" in nature, by that I mean that the melody or soprano voice (on top) and the bass line (on the bottom) are the two most active parts in the majority of music. The inner voices, the alto and tenor, have their moments certainly, but for the most part their role is to fill in the middle in the most sonorous way possible. Ergo, the two most important musicians on most pop records are the singer and the bassist. Now Motown's singers have become among the most famous in history (Stevie Wonder, Diana Ross, Smokey Robinson, Michael Jackson, Marvin Gaye, etc.), but the musicians who played on the records didn't. There was an attempt at redressing the situation with the 2002 film, Standing in the Shadows of Motown (which took its title from a 1989 book about Jamerson's life and work), and it did to a large degree - it's a great movie, by the way - but it came too late for many of the musicians, and particularly the most accomplished and most important artist on the label's roster. I'll be writing more on him in the days ahead, but for now here's a good example of his brilliance: http://www.youtube.com/watch?v=2JmVrkRcTgo