The time signature of a piece is determined by counting the number of beats in each bar and identifying the beat unit. Examining the bars in this tune:
Bar 1 contains a dotted minim (dotted half note), which is worth 3 crotchet beats.
Bar 2 contains a crotchet, two quavers, and another crotchet, totalling 3 crotchet beats (1 + 0.5 + 0.5 + 1).
Bar 3 contains a minim and a crotchet, totalling 3 crotchet beats (2 + 1).
Since each bar consistently holds 3 crotchet beats, the time signature is 3/4. This means there are three beats per bar, with each beat being a crotchet (quarter note). The key signature shows one flat (B♭), placing the tune in F major, but the time signature is determined solely by the rhythmic grouping within each bar.
