John has made about ten operatic reductions.

John's reduction of William Walton's opera Troilus & Cressida for the William Walton Trust was premiered by Opera Theatre of St Louis in June 2009 to great critical acclaim. In essence the work was reduced from triple to double woodwind with the brass reduced to standard orchestral size. The reduction gained wide critical acclaim: "Nothing about John Gibbons' reduced orchestration left one wanting for more" - Scott Cantrell - The Dallas Morning News.

John's reduction of Offenbach's Robinson Crusoe, for Opera della Luna, took a more extreme twist with the high violin lines of French Opera given to flute/piccolo and clarinet in a small chamber orchestra without violins.

In 2016 John produced a reduced version of La Traviata for a private performance in Wiltshire with a band of 14 players and a running time of 80 minutes.

For Opera Up Close John created reductions of L'Elisir d'amore and La Fanciulla del West.

"every so often, something comes along to knock your socks off. This will be hard to outdo as the operatic revelation of the year. ..Nothing about John Gibbons’s reduced orchestration left one wanting more."