It depends on what scale you're talking about.
B flat major = B flat, C, D, E flat, F, G, A
B flat harmonic minor (ascending and descending) = B-flat, C, D-flat, E-flat, F, G-flat, A (natural),...
b flat (half note), c, d, e flat, f, g, a , b flat (half note),a g, f, e flat, d, c, b flat b flat(half note), d, f, high b flat, a, f, e flat, c, b flat (half note), (divisi) f, e flat, d (or) d, c,...