Named artists where someone else does the vocals

[bugo]

David Guetta, Avicii, deadmau5, and any other EDM artists who only produce instrumentals with different vocalists.

Have you checked out BT? I assume you know who Bassnectar is. If not check him out as well.

[FightingIrish]

And in later years, they enlisted other singers (touring band members, etc.) to sing lead. "Sail On, Sailor" is a notable example.

I thought Blondie Chaplin was brought on as a member of the band at that point.

With bands like the Beach Boys that carry on for decades that becomes kind of a blurry line.

That's correct. Blondie sang lead.

[DandyDan]

From the realm of heavy metal, most of Yngwie Malmsteen's songs are sung by someone else.

[bugo]

Bassnectar
BT (sometimes)
Iommi
Vai
Deadmau5
Unkle