I am looking for some information on the 9th century Indian philosopher Vachaspati Mishra. Besides writing standard commentaries on practically all the Indian philosophical systems, this man is credited with having made original contributions in fields as varied as law and Indian classical music. Is there any book out there which gives some details about the contributions of this person(biographical details would be very welcome too)? Further, could someone tell me whether Vachaspati was affiliated to some particular Indian philosophical school?