Maslanka received his Bachelor of Music from the Oberlin Conservatory (1961–1965) and went on to earn a Master of Music and Doctor of Philosophy from Michigan State University (1965–71). During his undergraduate work, Maslanka also spent one year studying abroad at the Mozarteum in Salzburg, Austria (1963–64). While attending Michigan State University, Maslanka studied composition with H. Owen Reed. He served over 20 years on the faculty at Kingsborough Community College of the City University of New York and also served on the faculty at Sarah Lawrence College, New York University. Maslanka was a freelance composer and had worked solely on commissions from 1990 on. He lived in Missoula, Montana. He had two brothers named John and Robert Maslanka, who both are living in other parts of the U.S. He married Alison Matthews in 1981, who died on July 3, 2017, and is survived by three children: Steven, Matthew, and Kathryn.
