To me the term Holy Grail as used in your post means the sound, song or use of the instrument that moved me into a love for the Hammond organ. For me that was mostly Jimmy Smith. The video of Walk On The Wild Side that I linked to is a prime example; when he brings in the full drawbars on the second 5 chord at the end of the phrase shows how instantly dynamic the Hammond organ can be.

This can also be said to an extent with A Whiter Shade of Pale, but not quite to the same degree.

Sure, there are a lot of rock tunes as well as other styles that utilize the Hammond organ. I lean more toward groups like Santana and BS&T for some other great Hammond playing.

Another very great video I found a while back is one from the late, great Billy Preston. Check this out: http://www.youtube.com/watch?v=YlxxmNP2MKw
That is a Holy Grail moment if I ever heard one.

Wm. David McMahan
The Modulators

[This message has been edited by WDMcM (edited 11-01-2010).]