You can use a Color mix node set to "screen" mode, to mix the bump texture with the Musgrave texture, so that you get a dark value only where both textures are dark.
Remember that color ramp nodes generally have black on left and white on right side (if inverted the results are inverted).
All four last shader nodes can be substituted with a Principled BSDF (with different results).
This is another approach, in which two different shaders (one with bump ond one without) are mixed.
Pro: the two shaders can have very different values. Cons: slower render, as two shaders have to be evaluated instead of only one.