A lot of adjectives have been applied to George Strait albums over the years, but “surprising” isn’t usually one of them. And yet here is Twang, which finds the legendary singer taking several chances with his tried-and-true formula and seeing his bets pay off handsomely.

First we have the fact that George has, for the first time since 1982, contributed to the writing of several songs. The best compliment that can be paid to all three is that they blend in perfectly with the usual gems from superlative outside writers.

Another unexpected development is the debut of George’s son, Bubba, as a songwriter: His solo composition “Arkansas Dave” is the head-and-shoulders standout here, a taut narrative in the style of Johnny Cash’s 1960s cowboy parables. Closing out the album is a version of José Alfredo Jiménez’ “El Rey,” sung entirely in Spanish with a spirit of freewheeling derring-do that one rarely hears from such a reserved artist.

It’s an apt finish to one of the most diverse and satisfying albums of George Strait’s career.