Within the complex Boccherini catalogue, works that are listed in the title page as having possible substitutions by other instruments occupy an important role.
Sometimes this possibility is offered by the author himself, while in other cases it is the publisher's idea, in order to make the product more desirable, to distribute it to a wider public, and perhaps also to widen the not particularly rich repertoire of some specific instrument. It is interesting to understand how the composers behaved in making these changes, in compliance with the poly-instrumental eclecticism of many performers- that is, whether the composer may have called for genuine transformations in the original composition, or whether he may have concerned himself with writing in a "neutral" way, or whether he may not even have cared to adapt passages and ranges to the alternative instrument.
Some exemplary cases are considered here, particularly those of op. 41 and 42 n. 1 and 2, corresponding to corresponding to as many pieces in op. 38 of the so-called "autograph" catalogue (and to G 470, 471 and 467 respectively). Boccherini's attitude seems very avant-garde in that creative needs are subordinated to the needs of performance. The musical material is conceived and adapted in terms of context, sometimes and when necessary exceeding the traditional parameters of sound and technique.