In 1984 Gregg returned to the
United States, and together with
Joseph Curtin, founded the violin-making studios of
Curtin & Alf. His partnership with Joseph Curtin attracted the attention of numerous stars of the violin world, including Elmar Oliveira, Ruggiero Ricci, and
Zvi Zeitlin. In 1993 a Curtin and Alf violin made for Oliveira set a record at a Sotheby's auction for the highest price paid for a violin by a living maker.
[1] In 1997 he opened
Alf Studios at the same location in Ann Arbor.
Replicas of classic Italian instruments formed the basis of his early work. But, Gregg also uses science and technology to better understand the acoustical foundations of his craft. Since 1996 he has been a member and facilitator of the
Oberlin Summer Violin Making Workshops. In recent years he has become a recognized expert on the acoustical properties of violins.
[2] He has also received numerous awards from the Violin Society of America for his work.
[3]