In 1866-67 he taught at the Stern Conservatory in Berlin, succeeding Hans von Bülow, then resumed concertising.
In 1878 he took over the piano class of Theodor Leschetizky at the Saint Petersburg Conservatory, where his pupils included Vasily Safonov, Wassily Sapellnikoff and Genary Korganov.
Brassin's piano transcription of the Magic Fire Music from Wagner's Die Walküre was long a concert favourite, and has been recorded many times.
His other Wagner transcriptions from the Ring Cycle were: Valhalla, Siegmund's Love Song, Ride of the Valkyries (Die Walküre), and Forest Murmurs (Siegfried).
Pianists who have recorded these pieces include Josef Hofmann, Ignaz Friedman, Isador Goodman, Michael Ponti, Jean-Yves Thibaudet and Severin von Eckardstein.