The tour was to have featured Russian-born conductor Vasily Petrenko and Korean pianist Yeol Um Son.
O'Neill will perform a selection of songs by music greats Gustav Mahler and Richard Strauss.
The orchestra will also perform two works; Hector Berlioz's exuberant Le Corsaire Overture and Sergei Prokofiev's heroic Fifth Symphony.
Berlioz's Le Corsaire Overture was inspired by a voyage he made on a corsair sailing ship and reading Lord Byron's poem The Corsair.
O'Neill will perform Mahler's masterpiece Lieder eines fahrenden Gesellen 'Songs of a Wayfarer', inspired by the composer's infatuation with a soprano.
O'Neill will follow with six of Strauss' finest lieder; the song cycle Ruhe, meine Seele, Cacilie, Heimliche Aufforderung and Morgen, along with Allerseelen and Zueignung.
Prokofiev's Fifth Symphony premiered in 1945 to acclaim in the USSR and was also so popular with American audiences the composer featured on the cover of Time magazine.
Prokofiev wrote his symphony as the tide of World War II turned in the Allies' favour.
He described his work as "a symphony of the greatness of the human spirit, a song of praise of free and happy mankind".
Scholars have since speculated that it is also a call for artistic freedom.
After Spirit, the NZSO will resume its popular Shed Series concerts with Cadence in Wellington on August 28 and Auckland on September 4.
Passion will tour Wellington, Dunedin, Christchurch and Auckland in late August and September, followed by Inspiration in Wellington and Auckland, and Erocia in Gisborne and Kerikeri.
Tickets to Spirit are available via ticketmaster.co.nz. A livestream of the Wellington concert can be viewed at live.nzso.co.nz
