Why did a professional musician name galaxy catalog numbers that are still in use today?
The professional musician was William Herschel, who played music for a living before becoming an astronomer. This makes sense if you think of Kepler's music of the spheres. Assisted by his sister Caroline Letitia (1750-1848), he began a series of four "reviews of the heavens" in which he described the motion and the distribution of the stars. Not only did this provide the data to help substantiate Newton's physics, but it also led to a catalog of heavenly objects that still in use today - the New General Catalog of non-stellar objects.
Herschel produced the first rough description of our galaxy, the Milky Way, and calculated both the direction and velocity of the motion of our solar system through space. Despite all this, he did not know that many of the "faint fuzzies" or non-stellar objects were actually galaxies. These objects were not confirmed to be galaxies until well into the 20th century. Those NGC numbered galaxies we so blithely name were still mysteries when they were catalogued by Herschel during the time that Mary Shelly wrote Frankenstein.