As a side note, I play slack key on my ukulele quite often. The most common tuning I use is the ukulele " C Taro Patch" tuning which is GCEG (best with a low G ukulele). This gives you the same as if you had a guitar tuned to Taro Patch G and you barred (or capo'd) the top four strings at the fifth fret. You can now play lots of songs easily in the key of C and all the inners/outers are the same but for the C Scale.