It has been a while since I posted a good TV theme, so here is an eighties classic.
And here is the first theme… terrible!
From Wikipedia: The original theme music for the opening credits of the pilot episode was a mid-tempo jazzy piece by Ian Freebairn-Smith. This music was also used for the next nine regular episodes.
Beginning in Episode 12, it was replaced by a more uptempo theme typical of 1980s action series by Mike Post and Pete Carpenter with guitar by Larry Carlton. This theme had been used during the show and over the closing credits from Episode 8. A longer version of this second theme (“Theme from Magnum P.I.”, clocking in at 3:25) credited to Post was released as a 7″ single by Elektra Records in 1982 and featured on the Billboard Hot 100 chart that same year, peaking at No. 25 on 8 May 1982. This version also appeared on Post’s 1982 album Television Theme Songs.