Country star Glen Campbell has had his share of ups and downs in his more than four decades in the music biz, and now the "Rhinestone Cowboy" singer talks to ET about the hard times and the new good times, including his Meet Glen Campbell album.

"I really made some bad choices," Glen tells ET's Thea Andrews, going on to say, "Oh, it was bad, it was. Drugs, drinking. Stupid things that you do."

But Glen has cleaned up his act, and says of his life now: "It's wonderful. I look at people now and say, 'Wow, I was in that place one time.'"

One of the things that helped Glen heal was music. And now he's trying something new. In his just-released Meet Glen Campbell, he is covering new and old pop and rock songs, including Tom Petty's "Angel Dream" and "Walls," Travis' "Sing," and The Replacements' "Sadly Beautiful." He says there is no theme to the songs on this album, but they are all good.

"If they're good songs, you can put them anywhere, good is good in the music business," he says.