He revised the work considerably , mentored by Siegfried Palm .
The composer wrote a cello concerto in 1990 and played the solo part in the premiere in Yverdon , Switzerland , in June that year .
composer revised the work considerably , mentored by Siegfried Palm .
The composer wrote a cello concerto in 1990 and played the solo part in the premiere in Yverdon , Switzerland , in June that year .