Balynda Helene Benson-Gorelick and Kenny G.
Sara De Boer/Startraks
08/13/2012 AT 07:25 PM EDT
Seven months after their separation
, Kenny G has filed for divorce from his wife of 20 years.
The smooth jazz musician, 56, whose real name is Kenneth Bruce Gorelick, cites irreconcilable differences for dissolving his marriage to Balynda Helene Benson-Gorelick, according to his L.A. Superior Court papers filed Aug. 9.
He seeks joint custody for their minor child, 14-year-old son Noah.
Married in 1992, the pair separated last January and have a prenuptial agreement, the papers say.
Benson-Gorelick had filed for legal separation in January, also citing irreconcilable differences, and requested full physical custody of Noah.