Brady Singer came to Kansas City basically throwing two pitches, sinker and slider. He would throw the changeup in there every once in a while, but for the most part it was two pitches that did all the work.
From his Baseball Savant page, you can see how this pitch mix has gone through his 4+ years in the majors. This year, we see a fourth pitch show up on the chart, the four-seam fastball, though it is still used significantly less than his two pitches that have been the bread and butter of his career.