b is a flat sign. If it appears in the music score, it means that the original note is temporarily lowered, and the next measure has to return to the unflattened note. It is written after the clef, such as there is a b on the third line after the treble symbol. , there is a b on the second line after the bass symbol, which is the key signature, specifically the key signature of F major. When playing, just lower the note on this line by a semitone (that is, play the black keys).

It should be emphasized that the temporary flat mark only lowers the marked note, but the key signature must lower all the notes. For example, if the xi is lowered here, all xi in this piece of music must be lowered. When playing, the note with a line under it after the treble symbol is playing middle C.

Extended information:

Treble clef When the treble clef is used, it is also called the G clef, with the middle C (dol) on the bottom plus a line. The second line, which is the line where the pen starts when drawing the treble clef, specifies the pitch as G (sol).

When the bass clef is used, it means that the fourth line of the staff is f, also known as the F clef, and a line above it means middle C.

Alto clef Alto clef, also known as C clef, the third line position is middle C; tenor clef, also known as the fourth line position is middle C.

There are often some eighth notes or sixteenth notes on the staff (smaller than normal notes), with a small slash (short grace note) or not on the stem. With a small slash (long appoggiata), this small note is called "appropriate note".

Baidu Encyclopedia-Music Symbols