In 1995, Gareth Farr was commissioned to write the official piece for the NZSO's 50th birthday celebrations. Roger Lloyd, artistic manager of the NZSO at the time, chose him after being impressed by another of Farr's works, Tabuh Pacific, written for orchestra and Javanese gamelan. Lloyd's vision of the work was a multicultural piece, taking inspiration from music around the Pacific Rim. The piece was to be in two parts: a short impressive prelude followed by a more extensive tone poem - the total length being about 25 minutes. This was to give versatility to the work, so Part One could be played solely as a rousing concert opener or the whole work as a substantial concert item.
Farr contemplated adding ethnic performance groups with the orchestra for Sea Gongs, but eventually decided to use just orchestral instruments. His reasoning was that "this piece was a celebration of the orchestra, and the many wonderful sounds and textures it can produce." At the time, Farr was experimenting with ethnic instruments and ideas in his compositions, and trying to reproduce these sounds with an orchestra. This experimentation can be found in Sea Gongs, Tabuh Pacific, and various other works of his. Farr's music is influenced by his extensive study of Western and Non-Western percussion, with rhythmic and timbral elements of his music drawing from Pacific music such as Kapahaka, Rarotongan and Taiko drumming, Javanese and Balinese Gamelan and many others around the Rim.
Much of Pacific music revolves around percussion and rhythms, and Sea Gongs reflect this through Farr's use of percussion cadenzas. These feature three percussionists playing 10 roto-toms ranging in diameter from six to 18 inches. He used another piece he had written in 1993 as the basis for the cadenzas, reinforcing the "rock star impact" of the drummers by using it in contrast with the orchesral context. He decided to build up to these using the orchestra, "whip[ping]