I recently went to a ukulele meet-up to play some music and meet some people and I bought the song book that they use. It consists of mostly pop/rock songs and old folk tunes however, they have all been transposed to keys that are easy to play on the uke (C, F, G, D and, A). I am interested in now playing the songs along with the original records (just strumming the chords at this point) so will need to transpose them. As an exercise I’d like to do it in real time. So far I have tried:
just moving every chord up or down the appropriate interval which is easy for some jumps (up or down a step for example)
analyzing the song with Roman numeral notation and then using that to play in the new key. This is easier if the jump is hard to calculate in my head quickly but is hard for some chords like V/III.
Are there other methods of doing this. I know whatever method I choose will have its pros and cons and they will all take practice but just want to know if there are other options and what the pros and cons are?