Nathan Shahar first achieved fame as a composer, choir conductor and musical director of various radio and television broadcasts. A number of songs that he composed won prizes at song festivals. The main area of his musicological research is the musical and social-musical aspects of Hebrew song—a topic on which he has published a series of articles in Israel and abroad. These include the entry in the most recent edition of the Grove Encyclopedia on folk song in Erez Israel and the state, before and after the War of Independence. A new book on the history of Hebrew song is due to be published in 2005–2006.
Shahar has taught for many years both at Bet Berl College and also at the Ben-Gurion University of the Negev.