MEC 2021 BEST POSTER AWARD. The OpenScore Lieder Corpus is a collection of over 1,200 nineteenth century songs encoded by a dedicated team of mostly volunteers over several years. Having reported on the initial phase, motivations, design, and community-oriented aspects of the project before, we present here the first, stable, large-scale release of this corpus specifically designed for MIR researchers, complete with comprehensive, structured, linked metadata. The corpus continues to be available under the open CC0 licence and represents a compelling dataset for a range of MIR tasks, not least given its unusual balance of large-scale with high-quality encoding, and of diversity (songs by over 100 composers, from many countries, and in a range of languages) with unity (centred on the nineteenth-century lieder tradition).