We can all agree on the fact that our dogs look cutest when they tilt their head and we want the tilting to never stop. For the longest time I tried to figure out what is that sound that makes him do this so I can play that sound because couldn’t get enough of that tilt. Dogs do that when they hear something mysterious, a sound they have never heard before . They will tilt their head until they understand the sound or the source of the sound. When they are concentrating on something or deeply engrossed. But this tilts would be more frequent when they are young as they’d be new to these sounds as they grow up they become habitual to everything nothing fascinates them much like before. I would say just cherish these things as you won’t have them as he grows up and these tilts are something to die for.