As I was watching this drama I wrote a whole bunch of posts on the Feeds breaking down the dance scenes and otherwise discussing what the drama gets right/wrong in its portrayal of ballet. I probably annoyed people with my nitpick-y spamming 🙃, but I figure there might be the occasional person who doesn't have much familiarity with dance but would be interested to know, so I'm going to share/save all the posts I wrote here. 

Unless italicized, bold indicates a link.

Summary thoughts on the general execution of the dancing and the drama's overall portrayal of ballet

The following posts generally refer to specific scenes ...

Swan Lake performance / Shin Hye Sun’s dancing (episode 1 opening scene)

Swan Lake performance / Kim Bo Mi’s dancing (episode 2 @12.57)

ranks in ballet companies

rehearsal / artistic director (Ji Kang Woo) + ballet company names

Kim Bo Mi’s dancing / late night rehearsal (episode 4 @17:08) + Seoul Ballet Theater (they’re performing as the company in the drama) and Korean ballet companies

young Yeon Seo and Ni Na’s dancing / training in Russia (episodes 4 @17:24 & 5 @14:57)

American ballet companies (not very interesting)

rehearsal / Kim Bo Mi's dancing (episode 7 @21:27)

rehearsal (episode 8 @6:48) + soloists

costumes

Shin Hye Sun’s dancing / practice at the barre (episode 9 @20:59)

company class / rehearsal (episode 9 @29:24)

Shin Hye Sun’s dancing / practice with Kim Dan (episode 10 @0:20)

Shin Hye Sun’s dancing / practice en pointe (episode 11 @11:27 + brief note on practice scenes later in the episode)

the drama’s use of Giselle music in episodes 10-12

practice (episode 13 @14:07)    
I didn't write a post about this, but she rehearsing something approximating the end of Giselle Act II, starting when the bells ring, signaling the dawn (see this performance at 1:36:28), but it’s condensed (they skip a section of the music), not really timed right to the music, and done without a partner. Pointe work is the double.

class (episode 15 @20:10)    The actual class looks fine, but the cattiness is a bit over-the-top. Also you wouldn't stand that close together to begin with.

ballet storyline in episodes 13-16 + rant about Ji Kang Woo's choices as artistic director

auditions / Shin Hye Sun and Kim Bo Mi's dancing? (episode 20 @7:45)    This post is only about the performances by Shin Hye Sun and Kim Bo Mi's characters. The other 3 dancers are all performing a different, more technically difficult scene. The choreography they're doing is approximately correct, though not exact. At least one of them looked a bit sloppy.


Giselle performance Act I (episode 30 @14:37-18:21)

Giselle performance Act II / Shin Hye Sun and Kim Bo Mi's dancing (episode 30 @23:08-31:09)