Sonata Facile (K. 545, first movement)

Background

Mozart entered this sonata in his own handwritten catalogue of works on 26 June 1788, describing it as a little keyboard sonata for beginners. It was a busy summer: in the same weeks he was writing his last three symphonies, Nos. 39, 40 and 41. The sonata was not published until 1805, well after his death in 1791, and the nicknames Sonata facile ("easy sonata") and Sonata semplice were added by publishers, not by Mozart.

"Easy" is relative: the notes lie well under the hands, but every uneven scale can be heard. The sonata has three movements; this page is about the first, a bright Allegro in C major. The slow second movement is in the library as the Andante.

The movement has one famous oddity. In sonata form, the opening theme normally returns in the home key after the middle section. Here Mozart brings it back in F major instead (bar 42), and only later steers home to C.

How to practise it

Start with the left hand of bars 1 to 4. It plays an Alberti bass: a chord broken into the order low, high, middle, high, named after the composer Domenico Alberti, who used it constantly.

The left hand sits high, around middle C, so read it carefully if your copy uses a treble clef here. The thumb plays the repeated top note, and it should be the softest note of the four; let finger 5 carry a little weight on the beat. Practise it with a metronome until all four notes are even, then play it quietly enough to whisper under the melody.

Next, the scales in bars 5 to 12. Bar 5 runs up from A and back down; bars 6, 7 and 8 do the same from G, F and E.

To make scales even, practise them in rhythms: long-short, then short-long, then in groups of four with a pause on each first note. Keep the thumb moving under the hand early, so there is no bump when it arrives.

A suggested order:

1. Bars 1 to 12, hands separately, then together at 60 beats a minute.
2. The second theme, in G major from bar 13, where the left hand rocks between two notes under a decorated melody.
3. The middle section (bars 29 to 41), which travels through minor keys.
4. The return from bar 42, which repeats earlier music in new keys, so compare it with bars 1 to 28 as you go.

Raise the tempo in stages: 60, 80, 100, then the full 120. The style should be light and clear, with crisp endings to phrases, very little pedal, and the melody always above the accompaniment.

Bar-by-bar slow practice like this is explained in how to practise piano.