Mystery Shrub

This pretty purple shrub has been flowering for the last week or so in the garden and we have no idea what it is. I saw the same plant, together with a white variety which was scented (the purple one is not) at the Barnhill Rock Garden on Tuesday, but it had no name tag attached.

A friend has suggested it might be an Ajuga, but can anyone confirm this? I tried to find it in a couple of nurseries in Perth today, but with no success.

More street performers in town today, but these were an excellent jazz band of really talented players. Hard to say where they originated from, but possibly Eastern Europe. They had everybody smiling and toe-tapping to their lively music:-)