why is a crotchet called a quarter note
Quarter note A quarter note (American) or crotchet (British, from the sense 'hook') is a note played for one quarter of the duration of a whole note (or semibreve). Often, musicians will say that a crotchet is one beat, but this is not always correct, as the beat is indicated by the time signature of the music; a quarter note may or may not be the beat. Quarter notes are notated with a filled-in oval note head and a straight, flagless stem. The stem usually points upwards if it is below the middle line of the stave or downwards if it is on or above the middle line. However, the stem direction may differentiate more than one part. The head of the note also reverses its orientation in relation to the stem. (See image.)