The speaker, Ernest Mikleij, discusses Melrose, an open-source project he has been working on for a couple of years. Melrose is a combination of a language and a runtime that allows users to compose music using function abstractions. The language supports notes, sequences, progressions, and compositions, among other features, and can be interpreted using Go. The Melrose program uses MIDI to communicate with various MIDI devices, and it comes with both a binary version and a web version. The speaker demonstrates examples of composing music using Melrose and discusses the behind-the-scenes process of translating the language into MIDI events. The speaker also mentions the availability of pre-compiled binaries for Mac and Windows and provides resources for downloading Melrose and accessing its documentation. The talk concludes with a Q&A session, where the speaker answers questions about MIDI capabilities, Melrose's suitability for live coding, alternative projects, and potential integrations with other software.