Sound Theories vol. I & II is a 2007 album by American guitarist Steve Vai. The album was recorded with the Metropole Orchestra in Netherlands in mid 2004-2005 and released on June 26, 2007.
Volume I features Vai playing guitar with the orchestra, which has itself earned worldwide acclaim by backing artists ranging from Mike Keneally, Terry Bozzio, Tony Bennett and Natalie Cole to Nancy Wilson and the Yellowjackets. Unlike other solo albums, the new material on Volume II is devoid of Vai's solo guitar. However, despite this the album received much critical acclaim.
Volume II features the Orchestra performing compositions written by Vai, including “Shadows and Sparks” and “Bledsoe Bluvd.”