Burn a DVD (songs) to play on a regular CD player?

I am pretty sure the answer is no, for various reasons. The audio CD standard dates from the early 1980s long before DVDs existed so a CD player won't know what to do with a DVD. Your files are burned onto the DVDs as a data disc but an audio CD is its own format disc. Your files are mp3 format which is not standard CD format and requires a mp3 capable player. Apart from being able to interpret the files I don't think any standard CD player is capable of reading a DVD disc. You may find you could play the files in a television DVD player kind of like you can with a computer's optical drive. but I can't say they aren't set up to only expect video format to be present on a DVD and won't play it either (you'd have to try).

With Roxio Toast, you can make a data DVD of the MP3 files, or you can make a "music DVD" that will be written with a VIDEO_TS folder. As was pointed out though, the hardware in a CD player cannot read a DVD.