Conversation so far:
Whose independent career was this?
In the early to mid-1990s, Isaac, Taylor and Zac sang a cappella and recorded such classic songs as "Rockin' Robin", "Splish Splash" and "Johnny B.
Goode".
Which other songs did they record?
The band recorded two independent albums in their hometown of Tulsa, Boomerang (recorded in autumn 1994, released in 1995) and MMMBop (released in 1996).
Did those two albums feature their a cappella singing?
All three boys started their musical careers as pianists, but Isaac eventually started playing guitar and Zac started playing drums, while Taylor continued as the keyboard player.
Are there any other interesting aspects about this article?
The boys then found themselves at the South By Southwest (aka SXSW) music festival in Austin.
Did they perform at that festival?
There, they were promptly signed by manager Christopher Sabec.
He shopped them to several record companies.
Which record company signed them?
Mercury.
Did any other companies want to sign them?
After this performance, they were signed almost immediately by Mercury.

Question: What did they release under the mercury label?
Self-contained rewrite: What did Hanson release under the mercury label?