Two thumbs on one track for a span such as a note range, on Base UI's Slider. Controlled and told which thumb moved; labels point outward from their thumbs so they cannot collide, and the same formatter feeds aria-valuetext. Thumb hit areas are at least the sm control height (24px, 44 on touch). With keyboard the 24px piano strip is the track: one equal column per note, bar thumbs drawn on it, labels inline beside them, the range tinted with the value fill, pressing a key moves the nearer thumb, Shift+arrow jumps an octave.
pnpm dlx shadcn@latest add "https://pluginui.com/r/core-range-slider.json"