Happy Mother’s Day: Justin Bieber, Bruno Mars, Rihanna, Carrie Underwood, Kanye West Shout-Out Moms on Twitter

Justin Bieber/Twitter

May 12: Justin Bieber smooches his mom onstage during his performance of "One Less Lonely Girl" in Johannesburg, South Africa. See more photos of celebs with their moms here.

In honor of Mother’s Day, musical artists from across all genres are coming out of the woodwork to pay tribute to their moms on this special day.

Mother's Day Playlist: 20 Songs for Mom

In addition to Billboard’s Mother’s playlist - which includes everything from from 2Pac appreciating his mom to Danzig belting "Mother" in a hard-rock howl — we’ve compiled a list of our favorite tweets from artists who are recognizing the importance of their mother today. Also, click here to check out some of music's hottest moms.