 Skilled composers and conductors have this ability, with Beethoven being a noted historical example.Classical musicians playing orchestral works, chamber music, sonatas and singing choral works ordinarily have the sheet music in front of them on a music stand when performing (or held in front of them in a music folder, in the case of a choir), with the exception of solo instrumental performances of solo pieces, concertos, or solo vocal pieces (art song, opera arias, etc.