Thanks, Darkhammer.
Unfortunately I get the message 'no module named caplxxx'
And pip cannot find the module for me to install in python3 (it's there in pyuthon 2.7...):
pi@raspberrypi ~/drum-hat/examples $ pip install caplxxx
Downloading/unpacking caplxxx
Could not find any downloads that satisfy the requirement caplxxx
No distributions at all found for caplxxx
Storing complete log in /home/pi/.pip/pip.log