I'm late to this party but I feel like there's more to be said here.
People who are going to a beginning dance workshop of any kind are there, at least in part, to have fun. If it's a class for adults, odds are none of them are going to change careers to become professional salsa dancers, and if it's teens or younger children don't turn the youngsters off by being too strict! No matter the audience, let them have fun! I think showing them how to use the skills they're learning to dance to music they're more familiar with and, more likely to listen to in every day life, is a great way to do that.
Also, in my experience, a lot of people—especially high school or college aged girls and their mothers—who want to start learning salsa and other Latin and ballroom dance styles, have gotten interested in dance by things like Dancing With The Stars or Simply Come Dancing, where they salsa to pop songs all the time. The judges do point out that some of the songs they use aren't the best for salsa because the beat isn't quite right, but they still recognize that the dancers are able to demonstrate proper salsa technique regardless. This is what the non-hard-core-dancing public sees and is inspired by.
I'm rather disheartened to see so many people on this site who would cloud up and rain so hard on the idea of anyone ever dancing salsa to anything but “proper” salsa music because that attitude is bound to turn away laymen who would love to learn just for fun. Don't you want to share the joy that comes with your art?
Anyway, if Tom G or anyone else still needs songs, here are some that CAN be danced to:
“Instruction” by Jax Jones ft. Demi Lovato & Stefflon Don*
“Basketball” by Kurtis Blow*
“When I Grow Up” by The Pussycat Dolls*
“Fireball” by Pitbull*
"Magic" by Robin Thicke*
“Samba” by Bond
“Turn Me On” by David Guetta ft. Niki Minage
“Gangnam Style” by Psy
“Despacito” by Luis Fonsi and Daddy Yankee
“Creepshow” by Kerli Koiv
“Viva Las Vegas” by Aqua
“Shape of You” by Ed Shieren
Most of these aren't perfect, but they're all workable, and they're fun, popular songs the majority of people will have at least heard before. The first five which I've starred have been used on DWTS as salsas if you want reference, there are videos on youtube.