Trigger inverter

[E.B.Smits]

Hi all,
Now i want to make a trigger-inverter to convert positve triggers into
negative ones and back to.
By this i mean the triggers//gates for the input on my MS20 etc.
Sometimes i hear it's a real simple schematic with some capacitors and a
resistor or something.....
What is the configuration and what are the values????
Is it drawn somewhere on the web?
Will it work both ways? (+ to - and, - to +)

Could you please share the knowledge,
Thanks in advance,
ERiC

PS: a v/oct. to v/Hz converter would also be nice (more complicated ?)