to cover a wide range [from one thing to another]. She wants to buy the house, but her requests run the gamut from expensive new carpeting to completely new landscaping. His hobbies run the gamut from piano repair to portrait painting.
Extend over an entire range, as in His music runs the gamut from rock to classical. This expression alludes to the medieval musical scale of Guido d'Arezzo, gamut being a contraction of gamma and ut, the lowest and highest notes respectively. [Mid-1800s]