Andrew Manze has called him "one of the world’s foremost authorities on musical instruments.
In the 1970s he apprenticed with harpsichord builder John Challis and studied violin-making with Mittenwald faculty at the University of New Hampshire.
[3] In addition to his work there, Pollens restores stringed and early keyboard instruments for private collectors and museums (including an early New York piano for the Merchant's House Museum, an English bentside spinet for the Van Cortland House, and a Viennese fortepiano for the Morris-Jumel Mansion).
He has done keyboard restoration and recording preparation work for Leonard Bernstein, Paul Badura-Skoda, John Browning, Mieczyslaw Horszowski, Byron Janis, Igor Kipnis, and many others.
Among the more unusual instruments that he has restored are an accordion once owned by Alice "In Wonderland" P. Liddell and a tambourine painted by Toulouse-Lautrec.