London Obbligato Collective is a period-instrument chamber ensemble launched by the London-based harpsichordist Masumi Yamamoto in October 2023. It focuses on the unique genre of the "Accompanied Harpsichord Sonatas", an exciting body of repertoire in which the harpsichord is promoted from its traditional role of accompanying to the solo role. In this special genre, the harpsichord part is fully-written out by the composers and does not use figured-bass notation as expected in ensemble music from the eighteenth century. The harpsichord is given a place to shine, and colours and nuances of the harpsichord are effectively supported, highlighted and enhanced by the richness of the accompanying instruments.

The ensemble is made up of musicians who regularly play with the major period-instrument ensembles including the Gabrieli Consort & Players, the Orchestra of the Age of Enlightenment, The English Concert and the Academy of Ancient Music, and varies in size from 2 to 5 musicians of flexible instrumentation.

Britain was a real hub for this repertoire particularly in the North East and in London where composers such as Charles Avison (1709-1770), Felice Giardini (1716-1796), Carl Friedrich Abel (1723-1787) and Johann Christian Bach (1735-1782) wrote many pieces which give the harpsichord a prominent role.