B on Fiddle: the Numbers It Answers To
54 qualities on one root, each with the number that calls it.
Everything rooted on B, 54 qualities in 10 families. A chart will ask for three or four of them by number and leave the rest to the record, but the root is the part the number pins down, so this is the page a reader lands on first.
B answers to the 1, 2, 3, 4, 5, 6 and the 7 depending on what got called: it is a plain number in 7 of the twelve keys and needs an accidental in the other 5.
A fiddler reads a number as a set of notes to be inside rather than a chord to land on — the one reader on the floor who plays a line across the chart instead of a grip underneath it. One note at a time means the number is never played whole — it is outlined, and which of its tones gets outlined first is a decision made in the bar, not on the page.