The builder: Achim-Peter Gropius     This project could never have seen the light of day without the dedication of Reutlingen-based instrument maker Achim-Peter Gropius (www.gropius.de). I not only wish to thank him for his impeccable handiwork and artistry; the entire collaborative process was a joy, particularly in view of all the time he devoted to e- mails, sending photos, and exchanges on the telephone. In terms of timbre and optics, the result speaks for itself. I warmly recommend his services!