Final answer:
The pitch corresponding to the highlighted key on a piano could be D-flat or C-sharp due to enharmonic equivalence. In the scenario where adjacent piano keys F, F-sharp, and G are struck together, the beat frequencies produced are 21 Hz, 22 Hz, and 43 Hz, the differences between the frequencies of the notes played.
Step-by-step explanation:
The highlighted key mentioned in the question is the right-side black key of the three-black key group on a piano, which corresponds to either the pitch D-flat or C-sharp since a black key on a piano is named according to the adjacent white keys and can serve both a sharp of the white key to its left and a flat of the white key to its right. However, without the specific context of the key signature or surrounding notes, both names are technically correct as they represent the same pitch (this is known as enharmonic equivalence).
Beat frequencies occur when two tones with slightly different frequencies are played together, causing pulsations or beats that can be heard as a result of the interference between the two sound waves. When three adjacent keys on a piano (F, F-sharp, and G), corresponding to frequencies 349 Hz, 370 Hz, and 392 Hz, are struck simultaneously, the resulting beat frequencies will be the absolute differences between these frequencies. Therefore, the beat frequencies would be:
- The beat frequency between F (349 Hz) and F-sharp (370 Hz): 21 Hz
- The beat frequency between F-sharp (370 Hz) and G (392 Hz): 22 Hz
- Additionally, there would also be beat frequencies resulting from the combination of F and G, which is 43 Hz.
Beat frequencies are often used for tuning instruments to help musicians match the pitch of their instrument to a standard or another instrument.