Heinrich Friedrich Ludwig Rellstab (April 13, 1799 – November 27, 1860) was a German poet and music critic. He was born and died in Berlin. He was the son of the music publisher and composer Johann Carl Friedrich Rellstab.
Rellstab had considerable influence as a music critic and, because of this, had some power over what music could be used for German nationalistic purposes in the mid-nineteenth century. Because he had "an effective monopoly on music criticism" in Frankfurt and the popularity of his writings, Rellstab's approval would have been important for any musician's career in areas in which German nationalism was present.[1]
The first seven songs of Franz Schubert's Schwanengesang have words by Rellstab. His work was also set to music by Franz Liszt.
He is also known to have given Ludwig van Beethoven's Piano Sonata No, 14 in C-sharp minor, Op. 27/2 its famous nickname Moonlight Sonata.