“Mozart - Allegro - K. 3” is a short Classical piano piece in B-flat major. The music is written in 2/4 time and uses a bright, direct Allegro character with short melodic gestures, simple left-hand support, repeated phrase patterns, and clear dynamic contrasts. Even though the piece is small, it already shows a balanced Classical shape, with an opening section, a contrasting middle area, and a return to the opening material.

Measures 1–11 present the opening idea. The right hand begins with short, lively melodic figures, while the left hand supports with simple bass notes and small accompaniment patterns. The music moves between forte and piano, giving the opening a playful call-and-response feeling.

Measures 12–19 begin the contrasting middle section. The music becomes a little softer and more connected, with the right hand moving through small slurred figures while the left hand keeps the harmony steady underneath. The mezzo piano and piano markings make this section lighter than the bold opening.

Measures 20–30 return to the stronger opening character and bring the piece to a clear close. The familiar short figures and simple accompaniment come back, with forte, piano, mezzo forte, and final forte markings shaping the ending. The repeat sign at the end gives the piece a compact rounded form.

Interesting fact: Mozart wrote “Allegro” K. 3 when he was still a very young child, around the age of five. It is one of his earliest surviving keyboard pieces, showing how quickly he was already learning to organize melody, rhythm, and form in a clear Classical style.