Beat, rhythm and tempo

These two words get used interchangeably in ordinary speech, and keeping them apart makes everything downstream easier.

Beat is the steady pulse underneath the music — what you tap your foot to, or what a metronome clicks. It does not change when the melody does.

Rhythm is the pattern of note lengths played against that pulse. It moves; the beat does not.

Both bars last the same length and have the same pulse. Only the second one has an interesting rhythm.

Why the distinction matters

When you cannot play a passage, the fix depends on which one is wrong:

• If you are losing the pulse, the answer is a metronome and slower tempo.
• If the pattern is wrong against a steady pulse, the answer is counting the subdivisions aloud.

Treating a rhythm problem as a tempo problem — just playing it slower without counting — is the most common wasted practice hour in music.

Tempo is how fast the beat goes

Tempo is the speed of the beat, usually given in beats per minute. ♩= 120 means 120 beats a minute, or two per second.

Change the tempo and every note value changes together; the rhythm — the relationships between the lengths — stays identical. That is why note values are defined as ratios rather than in seconds.

Traditional Italian tempo words give a range and a character rather than a number:

The ranges are conventions, not rules, and they vary by period and editor.

Metre groups the beats

Beats are not felt as an undifferentiated stream. They group — usually in twos, threes or fours — with the first of each group feeling strongest. That grouping is metre, and it is what a time signature declares.