I see vegetative aberrations in one or two plants every year. First ones eaten.

There are various oddballs with garlic. Actually I like to plant those oddballs, just to see what they grow into....

The problem with replanting aberrant stock is that disease could be the cause of the deformity. When we had the Aster Yellows outbreak in the Midwest (which destroyed most of the garlic in the affected area), the disease caused unusual deformities, such as causing hard neck garlics to bloom, rather then form bulbils. Aster yellows is systemic, so all parts of the plant are infected... as would be any stock grown from infected cloves.

My Japanese frequently behaves like that right down to the large stem bulbil. The rest of my garlics don't seem to have picked up anything from it; so I would guess this is just an oddity. Could be anything causing it perhaps even a leaf developing that never opened properly and so closed off path the scape would use. IMO What you have is an aborted scape that broke out around a blockage of some sort in the pseudostem.

I would eat this one. One of the strengths of Music is how big and robust it grows with very little aberrancy.