The most memorable moments from the 2014 CMA Awards

From pop singers and classic rock bands crashing the proceedings to a couple of surprisingly progressive award winners, the 2014 CMA Awards on Wednesday night offered a number of memorable moments. These were the most unforgettable highlights from country music's biggest night.

Miranda Lambert sings "All About That Bass" with Meghan Trainor

Pop newcomer Trainor has written songs for country acts like Rascal Flatts in the past, so her presence at the CMAs wasn't all that strange. She teamed up with Female Vocalist of the Year winner Miranda Lambert for a cute, if by-the-numbers, rendition of her No. 1 hit "All About That Bass."

Michael McDonald and the Doobie Brothers sing their hits

One of classic rock's greatest acts got two opportunities to perform, first with "Listen to the Music" and later on "Takin' it to the Streets." Sugarland, Hunter Hayes, Lady Antebellum and others joined the Doobies on stage, but they were just complementary players, because it was the Doobies' iconic songs that took the spotlight. Not coincidentally, the Doobie Brothers just released a new album of their old hits re-recorded as duets with country artists.

Ariana Grande performs with Little Big Town

Little Big Town kicked off the performance by singing their excellent track "Day Drinking" while wearing light-up clothing that flickered red and black. Before long, they were joined by the 21-year-old pop diva-in-training, who sang "Bang Bang" while Little Big Town provided background vocals. This was the most unusual collaboration of the evening, but it seemed to work.

Luke Bryan wins Entertainer of the Year

Bryan had won this award at other country music shows, but last night was his first Entertainer victory at the CMAs, and it was well-deserved for the incredible run he's had with his Crash My Party album. Bryan's win followed a strong performance of "Roller Coaster."

Loretta Lynn duets with Kacey Musgraves

Cross-genre duets were all the rage at the CMAs, but the best collaboration was the most traditional country song of all. Kacey Musgraves began singing Loretta Lynn's classic "You're Looking at Country" in front of a Grand Ole Opry barnyard set when the 82-year-old came out to join the young superstar. Lynn has been singing since 1959 but somehow still seemed ageless.

Blake Shelton and Miranda Lambert dominate for the fifth straight year

The husband and wife team and Shelton and Lambert once again won Male and Female Vocalist of the Year, marking the fifth consecutive year they have dominated those categories. Despite heavy competition in both categories from artists like Luke Bryan, Eric Church, Kacey Musgraves and Carrie Underwood, Blake and Miranda will continue to carry the CMA torch for at least another year. Lambert also won three other awards, including Single and Album of the Year.

Kacey Musgraves wins Song of the Year for "Follow Your Arrow"

Of all the big moments on Wednesday's broadcast, the one that may have the most lasting impact was Kacey Musgraves' surprise Song of the Year win for "Follow Your Arrow." Seeing Musgraves on stage with her two openly gay co-writers, Shane McAnally and Brandy Clark, receiving the Country Music Association's highest songwriting honor for a track that endorses same-sex relationships was a sight that would have been impossible to imagine at the CMAs just a few short years ago.

Musgraves was well aware of the historical significance of the moment. "Do you guys realize what this means for country music?," she shouted.