Apple music songs A to Z index

[Macsync]

Can someone tell me what the ? symbol means in the A to Z index section of songs in ios10 , it is at the bottom after the hash symbol. I have now got around 200 tracks in there. Thanks

 

[Just_Me_D]

I don't know and I don't have a question mark displaying after the Hash mark.

 

[Macsync]

I have attached a screen shot, hope it helps. Thanks

 

[SwitchBeach]

Perhaps one or more song titles start with something other than a letter or a number. Or are corrupted.

Did you scroll down there to see what songs are there?

 

[Macsync]

Problem solved ! all the tracks in question had the compilation box ticked in the get info screen.