A piano concerto is a type of concerto, a solo composition in the classical music genre which is composed for a piano player, which is typically accompanied by an orchestra or other large ensemble. Piano concertos are typically virtuoso showpieces which require an advanced level of technique on the instrument, including melodic lines interspersed with rapid scales, arpeggios, chords, complex contrapuntal parts and other challenging material. When piano concertos are performed by a professional concert pianist, a large grand piano is almost always used, as the grand piano has a fuller tone and more projection than an upright piano. Piano concertos are typically written out in music notation, including sheet music for the pianist (which they typically memorize so that they can play the concert without sheet music), orchestra parts for the orchestra members, and a full score for the conductor, who leads the orchestra in the accompaniment of the soloist.