And then his tone brightened.

He recognized her voice, and his tone brightened.

The tone brightened a trifle.

Johnny asked, his tone brightening.

The tone brightens again as Trygaeus returns to the stage, dressed for the festivities of a wedding.

His tone brightened a little.

His tone had brightened, knowing I was a sailor.

"I have to go, darling," Bruckner said, his tone brightening.

Then her tone brightened.

"Here's an idea for you," he offered, his tone brightening considerably.