She finished her master's degree in 1941, and then went to Columbia University to pursue doctoral studies, and received Columbia's first doctorate in musicology in 1945 at age 22. Newlin's doctoral dissertation was published in 1947 as the book "Bruckner, Mahler, Schoenberg". A revised and expanded version was issued by W.W. Norton, New York, in 1978. While at Columbia she studied with among others Roger Sessions, Artur Schnabel, and Rudolf Serkin. Her thesis advisor and the university's department head at the time was Paul Henry Lang – as Newlin reports "no fan of Mahler, Bruckner or Schoenberg, but objective enough to support a student's authoring a good dissertation about them".