Jon Burlingame For a film or TV composer, the most difficult assignments are often documentaries. There is usually very little money, and finding the right tone and musical approach can be a weeks- or months-long challenge. Three of this year’s entries in the Emmy category for original documentary score are exemplary for their musical depiction of people and places: John Powell’s music for “Still: A Michael J. Fox Movie,” about the actor and his Parkinson’s condition; Blake Neely’s score for “Pamela, a Love Story,” about former “Baywatch” star Pamela Anderson; and Erica Procunier’s music for the three-part nature series “Great Lakes Untamed.”