I haven’t updated the percussion section in quite a while. Here’s a quick remedy.
First off, what is a gong? By definition, a gong must have a definite pitch. Therefore, the term “Tuned Gong” is redundant. I use this term however because many times the term gong, especially in traditional orchestral scores, actually refers to a tam-tam. Tam-tams will never have a definite pitch. Tam-tams will have a flat surface, while often, gongs will have a raised center (called a nipple), though, this is by no means always the case.
Tuned Gongs will have a chime-like quality to their sound. They will have the “splash” associated with a tam-tam at higher dynamics, but the pitch center will disappear. Strict “in tuneness” is not a given with gongs as the act of sticking them will cause some pitch distortion, especially at higher dynamics.
Pitches available will vary widely. Full chromatic sets are (or in some cases were) available from noted manufacturers. A quick Google search shows that I can find pitches available from B-flat1 to C6 – just over four octaves. (In case you’re curious, the total set is over $40,000.) Individual gongs are usually purchased for the needs of a particular composition rather than full sets. A complete set will be rare, but not impossible. http://www.steveweissmusic.com/product/tuned-thai-gongs/gongs
One major concern is space. These instruments, when all put together will take up a large amount of real estate. Performers will come up with all sorts of creative ways to arrange the instruments on stands, but with the lower pitched gongs, there will be large distances covered (sometimes feet or tens of feet).
One other concern is the length of each strike. Left to their own device, a gong will resonate for a long time (though not usually as long as a Tam-Tam). Specific durations will need to be dampened by the player’s free hand or by a second player. Larger gongs have longer durations than so smaller gongs.
Vaughan William’s 8th Symphony. This movement focuses on the tuned percussion and includes a major part for tuned gongs. One of the great master’s overlooked works.
This video of Et exspecto… starts in the 5th Movement where there is a significant accompaniment from the gongs. Note how the player has his gongs arranged. Also note how, at 32:53 one of the gongs goes flying off the stand ne’er to be recovered.
Oh, the perils of percussion…