Conversation so far:
When did the band break up?
The duo split up in February 1968.
What was the reason for the split?
a breakup that would last for more than six years, when Medley left to pursue a solo career.
Did Medley release any albums during this time?
Medley recorded a few solo recordings on several labels.
What was Hatfield doing?
Hatfield and Jimmy Walker recorded an album, Re-Birth, as "The Righteous Brothers" before disbanding in 1971.
How long were Hatfield and   Walker together?
before disbanding in 1971.

Question: Why did they disband?
Self-contained rewrite: Why did Hatfield and Walker disband?