Tip: By pressing Shift while placing event tiles, they will be made "silent" and will not appear until a map transition happens. Always use silent event tiles to draw paths in other maps (i.e. a Vanilla Dome event while the player is on the main map), or glitchy tiles may appear.
Uh, I just checked and 'stringslow.brr' is two notes higher than 'strings.brr'.
Both instruments should be tuned at a C if the tuning is applied.
Unlike strings.brr, stringslow.brr is only used for very low string notes in the original game so it's best to use strings.brr for melodics.