In the falling tone accompaniment, the pitch is lowered on the basis of the original scale. Using music notation means adding a lowercase letter B in front of the note, which is usually located in the upper left corner of the note.

When reading the notation, if you find such a lowercase letter B, you should consider playing this note in a falling tone. The sound of music can be divided into treble, midrange and bass, and the falling tone is actually the performance logo of the bass part.

on the basis of the original scale, lower the pitch, for example, D is lowered to C and A is lowered to G. You can also lower the pitch in the form of a semitone, such as B falling to B(bB), E(bE) falling to D, and so on.

rules of flat

one flat major or d minor, two flat major or g minor, three flat major or c minor, four flat major or f minor, five flat major or b minor, six flat major or e minor, and seven flat major or a minor.

eight flats are in f flat major or d flat minor, nine flats are in b flat major or g flat minor, ten flats are in e flat major or c flat minor, eleven flats are in a flat major or f flat minor, twelve flats are in d flat major or b flat minor, thirteen flats are in g flat major or e flat minor, and so on.

Pay attention to the observation rule: every time the number of flat signs increases, the tonic in major and minor (that is, the sound represented by the letters in the key names) decreases by a pure five degrees. In major, for example, if F is reduced by five degrees, it means B, B by five degrees, E by five degrees, A by five degrees, D by five degrees, G by five degrees, C by five degrees and so on. This is called "circle of fifths in Tone". Of course, most of them are from one flat sign to seven flat signs.