Wolfgang Amadeus Mozart's Piano Sonata No. 17 in B major, K. 570, dated February 1789, is a sonata in three movements:
A typical performance takes about 18 minutes.
The work is part of a commission by the court of Frederick William II of Prussia for six easy piano sonatas for Princess Frederica in May 1789 during Mozart's Berlin journey.
There is an accompanying violin part of doubtful origin in many 1800 editions; the piano part is exactly the same as for piano solo. Neue Mozart-Ausgabe (NMA) describe it as an addition by either Johann Anton André or .