The closest on my shelves to Riley (other than Wolfgang Rihm, but I’ve done Rihm already): Wallingford Riegger and Jean-Joseph Rigel. So I transferred my Amazon reviews of Riegger (1885-1961) – a pet composer of mine, an all-but forgotten American modernist and maybe the most unjustly neglected “important American composer” of the 20th century, one of the first introducters of Schoenberg’s Twelve-Tone technique in the US but also an eclectic, and a composer and orchestrator of great imagination and whimsicality.
And now, Rigel (1741-1799, an all-but forgotten French composer from the end of Ancient Regime and Revolutionary era).