Originally Posted by: isit2late?Will someone please tell me the chord progression for a plagal cadence in the key of open G? thanks

The plagal cadence is IV - I. The "four chord" resolving to the tonic "one chord".

In the key of G major, this would be:

C (IV) - G (I)

You can build virtually any chord progression to use before you get to the cadence at the end of the phrase, progression or melody. A very typical example would be:

G (I) - D (V) - C (IV) - G (I)

The Beatles song Let It Be uses lots of plagal cadences (although it is in C major).

http://www.guitartricks.com/tutorial.php?input=1786

Lots of pop songs use the plagal cadence with this common chord progression.

G (I) - D (V) - Em (vi) - C (IV) repeat or end at - G (I)

But always remember, even if songs share common chord progressions or cadences, the most important & crucial difference is found in the melody. Hope this helps!