In the 1980s professional percussionists from the two major New York City orchestras listened to almost 40 different head types. Four 1-1/8 models, OR39 (brown), OR42 (tan), OR45 (white) and OR48 (black) were selected as having the most frequent application to the major orchestral keyboard parts of the late 19th and 20th centuries. They are still found in the mallet bags of many professional percussionists.
Today there is a demand for models targeted for very specific excerpts, as well as a movement toward lighter, smaller heads for certain applications. There is no greater expert on orchestral keyboard repertoire than William James, principal percussionist of the St. Louis Symphony. Will has expanded the original OR line into a vast selection of sounds and tone colors, with many different materials, weights, sizes and handle types. Malletech makes history again with three different levels of fiberglass handle flexibility on the Mini-Glock models: Black, Red and White – expertly paired to the weight of the mallet head.
https://malletech.com/mallet-series/new-orchestral-series/