Lady Gaga has never been the most polite award show attendee. She pretended to die on stage and ended up covered in blood during her performance at the 2009 VMAs. The next year, she wore a dress made of raw meat. At the Grammys in 2011, she hatched her way out of an enormous egg. Her shows were dramatic and often controversial, which is why ears perked up when the Oscars began marketing this year's show with her name.

She didn't arrive in monster form, though. For her Oscar debut, she donned a white, floor length ball gown with blonde hair extensions, and paid tribute to the 1965 Best Picture-winning musical The Sound of Music. She sang a five-minute medley of "The Hills Are Alive," "My Favorite Things," "Edelweiss" and "Climb Every Mountain."

She was phenomenal. Throughout the entire performance, she only moved to dramatically lift her skirt or throw an arm out to the side. The focus of the audience, for once, was on her voice.

But Gaga has always been an incredible musician and vocalist. Her talent isn't new — it was discounted because many people didn't like or understand her style of artistic expression.

Lady Gaga has always been an incredible vocalist

Gaga was better known for her stunts than her abilities during the height of her fame in 2009. People wanted to talk about her costumes and her wigs more than they wanted to listen to her music. But what Gaga did last night at the Oscars was give them absolutely no choice. Her performance was minimal and the background almost disappeared. It was Lady Gaga at her most accessible. But it certainly wasn't some dramatic transformation.

Lady Gaga was born Stefani Germanotta, and grew up playing music and performing in stage shows. As a child in New York, she learned to play classical piano, trained with Christina Aguilera's vocal coach, and studied music history carefully. She attended NYU's Tisch School for the Arts where she became interested in performers like Elton John and glam-rockers like Queen, an obsession that would carry over to her performances at the height of her fame.

But this Gaga, the vocalist with a slightly-over-four-octave range and one of the best tones in popular music, has always been there. Here's Gaga performing as an NYU student.

And here's her at the 2010 VMAs where she performed with Elton John at a double piano:

Watching Gaga perform live is watching an artist, but it's also watching a truly great vocalist. She isn't lip-synching. She isn't singing her songs the way they're performed on the albums. She's shaking up the melodies, and switching the keys. She's demonstrating that she's not just a boombox, she's a vocalist.

Her voice isn't new. It's been there all along. So why did people seem so surprised to hear her sing at the Oscars?

Why we discount pop stars

Pop stars stay popular by following and breaking trends strategically. When Lady Gaga entered the public consciousness, pop was a bland game for the most part. When Gaga came to fame in 2008, the pop market was pretty saturated with female vocalists who played piano. Leona Lewis, Alicia Keys, Jordin Sparks, and Sara Bareilles were the top four female vocalists, according to the Billboard charts. (Further down the list were the future big names of pop — Katy Perry and Rihanna and Taylor Swift.)

In August of 2008, Gaga dropped The Fame, but the album was a sleeper. The lead single "Just Dance" didn't hit the Billboard Top 100 until January of 2009 when the world was ready for something new, bolder, and stranger.

Take Gaga's 2011 Grammy performance of "Born This Way" as an example. This is a mild piece of performance art for her. Sure, she emerges from an egg at the beginning and has some overdramatic eye make-up, but in general this is a pretty standard pop routine — there's a dramatic intro, a dance number, a break down, and a fiery conclusion.

But compared to an Alicia Keys performance, what Gaga did was insane. It also rocketed her to an unbelievable amount of fame. That was strategic on Gaga's (and her management's) part, and she wasn't the only one doing it. Nicki Minaj, Katy Perry, and Gaga were all wearing absurd costumes and pushing the limits of what popular could be.

It's that construction, that careful deliberation and decision-making, of pop music that many people use to completely discount an entire genre. Take one of the biggest criticisms of Beyoncé after this year's Grammy debacle with Kanye West: people declared earnestly that Beck deserved to win Album of the Year because he played 14 instruments, while Beyoncé needed four people to write a song.

That criticism ignores the impact of both artists, and instead places their value on a countable element. It ignores natural talent. It also assumes that Beyoncé needs more writers because she is not as good an artist, not because writing a pop song is an inherently more competitive, and thus more difficult, task.

That construction, of course, can be manipulated for evil, and place people with bad voices and little talent into the spotlight, but rarely do those people make it for long. They get caught lip-synching or flub their choreography. To stay a pop star requires the same amount of ability as any other genre, but not all of it is musical. Pop music is discounted because it requires more than musical ability to succeed. It requires a certain look, a certain sound, a certain willingness to transform and push limits that other genres don't.

The New Gaga is easier to accept

The thing about Gaga, though, is that she has always had the musical training to make her acceptable to music snobs and pop haters alike. They just ignored that. Any time Gaga played live, she was phenomenal. She sang with grit in her voice and a range to envy. She played the piano constantly in various insane wardrobes and never missed a note. Whether she was singing a pop song in a blue suit set and sunglasses or singing The Sound of Music at the Oscars shouldn't have mattered. But it did.

As Spencer Kornhaber wrote for the Atlantic:

"Back then, she used bizarre clothes and brash, earnest rock music to dramatize the idea that being true to one’s own desires and identity was a radical act—that people might make fun of you, but that a community of like-minded freaks would always have your back. Her move to classic styles visually and sonically isn't necessarily a rejection of that idea; she feels like singing cabaret, and so sales be damned, she's doing it."

Ultimately, accepting Lady Gaga in a white ball gown being hugged by Julie Andrews is a hell of a lot easier for the American public than to accept a woman in sparkly sunglasses and no pants as an artist. But it's the exact same construction of image that she underwent in 2008. Singing with Tony Bennett on his most recent album, and at the Grammys in a pin-up-esque dress, is image construction.

This time, Gaga's dressing up as a nice girl instead of a radical monster, and so she's easier to accept as an artist and a musician. But Gaga was just as talented when she was radical as she is right now.

WATCH: 'The anatomy of Taylor Swift's new hit, Style'