Final answer:
Ragtime piano music usually employs a 2/4 meter, characterized by a left-hand march tempo and syncopated melody. For piano tuning, beats are used to identify slight discrepancies in pitch between strings or between a string and a tuning fork, allowing the tuner to make precise adjustments.
Step-by-step explanation:
The meter generally used by ragtime piano music is 2/4. Ragtime emphasized its unique syncopated, or 'ragged', rhythm using a steady left-hand that played the bass note and chords in a march-like tempo, while the right hand played the melody with a bouncing rhythm, characteristic of the ragtime style.
When tuning a piano, if the middle C hammer hits two strings producing beats of 1.50 Hz and one of the strings is already tuned to 260.00 Hz, the other string could be slightly out of tune, either at 258.50 Hz or 261.50 Hz, as the beats occur due to the interference of two frequencies close in pitch.
Similarly, when a piano tuner hears a beat every 2.00 s (0.5 Hz) using a 264.0-Hz tuning fork, the piano string could be at 263.5 Hz or 264.5 Hz as those would be the two possible frequencies that could produce such beats in conjunction with the tuning fork's frequency.