Yesterday, in the car, Isaac suddenly breaks into song.
Nana Nana Na Naa
Nana Nana Na Naa
Nana Nana Na Na Na Naa
Nana Nana Na Naa
Nana Nana Na Naa
Nana Nana Na Na Na Naa
It sounded familiar, until we realised he was singing Engelbert Humperdinck's "A Man Without Love".