Hi @mrbombmusic and thanks for replying (and even bigger thanks for your indispensable tutorial series too!!).
I will def check out those two links, but I am aware of the repetitive results when trying to randomise a random seed (after watching and digesting every single one of your videos) 
. And I chose the upper bound 50 because it gives me ‘some’ randomisation, any lower and the random seed sticks in predictable ways.
Is using Time.now computationally expensive? I’ll give it a rattle and see what effect it has.
Thanks again
PD-Pi
ps I’m having waaaay too much fun with :pluck this week, and have written a really cool generative plucked/bowed autoharp thingy, which I may integrate with the melody generator above. Video coming soon 