[78-L] What's My Line?

[simmonssomer]

As this list boosts (boasts) the most knowledgeable 78 rpm collectors, 
archivists and discographers,  I feel confident that at least one of us can 
solve this puzzler.
The question is...what do the following 78's have in common.

Bluebird B-6071
Vocalion  03046
Decca 7114
Vocalion 03604
Decca DE 17329
Vocalion 3804
Decca 7476
Decca 7522
Bluebird B-8403
Bluebird B-8382
Okeh 6475
Okeh 6720

Al S.