Final answer:
F sharp is the musical note one semitone higher than F, and it is represented by the first black key to the right of the white F key on a piano. Beat frequencies occur when notes with close frequencies are played together, such as F, F sharp, and G with frequencies of 349, 370, and 392 Hz respectively.
Step-by-step explanation:
The note F sharp is a musical note that is one semitone higher than an F and one semitone lower than a G on the chromatic scale. In terms of piano keys, if you look at a piano keyboard, F sharp is the first black key to the right of the white key F. When multiple notes like F, F sharp, and G are played together, they can produce beat frequencies due to their close frequencies. If F, F sharp, and G have frequencies of 349, 370, and 392 Hz respectively, then the beat frequencies generated are the differences between these frequencies, namely 21 Hz (370 Hz - 349 Hz) and 22 Hz (392 Hz - 370 Hz).
In a broader context, musical notes like F sharp are fundamental building blocks of a song, and their frequencies are vital in achieving harmonious sound. For example, the standard tuning of guitar strings is based on specific frequencies to produce the standard notes when plucked.