Motivated by challenges involved in the long-term maintenance of digital musical instruments, the frustrating problem of glue code, and the inherent complexity of evaluating new instruments, we developed Sygaldry, a C++20 library of digital musical instrument components. By emphasising the development of components first and foremost, and through use of C++20 language features, strict management of dependencies, and literate programming, Sygaldry provides immediate benefits to rapid prototyping, maintenance, and replication of DMIs, encourages code portability and code-reuse, and reduces the burden of glue-code in DMI firmware. Recognising that there still remains significant future work, we discuss the advantages of focusing development and research on DMI components rather than individual DMIs, and argue that a modern C++ library is among the most appropriate realisations of these efforts.