Both Uses of

muster
in
All's Well That Ends Well, by Shakespeare

Use a more spacious ceremony to the noble lords; you have restrained yourself within the list of too cold an adieu: be more expressive to them; for they wear themselves in the cap of the time; there do muster true gait; eat, speak, and move, under the influence of the most received star; and though the devil lead the measure, such are to be followed: after them, and take a more dilated farewell.†
Scene 2.1 *

muster = gather

Let me see: Spurio, a hundred and fifty, Sebastian, so many; Corambus, so many; Jaques, so many; Guiltian, Cosmo, Lodowick, and Gratii, two hundred fifty each; mine own company, Chitopher, Vaumond, Bentii, two hundred fifty each: so that the muster-file, rotten and sound, upon my life, amounts not to fifteen thousand poll; half of the which dare not shake the snow from off their cassocks lest they shake themselves to pieces.†
Scene 4.3

Definitions:

(1) (muster as in: muster strength or the crew)
to gather
The exact meaning of this sense of muster is often subject to its context. For example:
- "mustered her courage/strength/a smile" -- to gather from within
- "muster the soldiers/crew" -- to gather -- typically for inspection
- "muster volunteers/votes" -- to gather enough to do something
(2) (muster as in: didn't pass muster)
inspection -- especially of soldiers or a crew
(3) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

More rarely, muster can refer to a counting or census. Much more rarely, muster can refer to a call to duty such as compulsory military service or jury duty. In that sense, you may see the expression muster in or muster out. Still more rarely, a muster can refer to a group of peacocks.