Who in your opinion is the modern day equivalent to Mozart?

ITT: people who have severely underestimated Mozart's musical capacities and contributions.
Mozart is a musician that is studied by nearly any professional musician. There are historians, musical scholars, and museums dedicated to him. He's a household name across the world. He established a period of music. As a teenager, he deciphered a 12 min choral piece with multiple groups and solos after hearing it once and by memory wrote it down later that night (he heard it a 2nd time a few days later for minor corrections). When he presented the score to the clergy, they said he got one note wrong. After investigation, Mozart heard it right. The musician's score was off by a note. Could any popular musician mentioned here decipher just a 6 min song of 4 instrument band after hearing it once with pen and paper ready? Imagine telling any music legend now, "Hey, you're off by a half a step on the 3rd note of bar 28 of your own song."
Comparing an awesome popular singer, guitarist, or band to him is like comparing your friend that got a job at NASA to Einstein. There is no modern Mozart. There have been greats since Mozart, but there haven't been any Mozarts since Mozart. I say this as a Beethoven fan. Mozart was the only Mozart. He was so good, that his name became a title for great musician: Mozart. No one listed in this thread is anywhere near being a Mozart.
- When you put it that way, the list of candidates thins out and the one figure I see still standing is John Coltrane, who in his day was running circles around fellow jazz musicians, they couldn't wrap their heads around how Coltrane's chord progressions and jumping between keys from note to note made any sense... yet it did, and beautifully.
  EDIT: typo
- No offence but I think you’re forgetting about Fred Durst.
  
  He literally broke stuff
- Likely the closest I could picture in a modern sense is Jacob Collier, who can indeed perform these types of musical feats. But the crux of the issue is that while Collier is much loved, he isn’t a dominant force of popular music like Mozart was.
- What if some or most of those details were made up to sound nicer / more impressive?
  
  Yeah, that's exactly my first thought while reading this. If I rewrote the list of achievements above to sound like I was claiming they all happened to me, and then posted it to twitter, it would be indistinguishable from most other "🙄 that happened" posts.
  People will be saying similar stuff about Taylor Swift in 100 years; by definition being legendary means being unreal.
- Honestly, I could see Jacob Collier doing just that.
- I agree, and this is easily my favorite post of the month.

Ummm
Prince.
Music fell out of him. He accidentally walked by a bass and it exploded from the funk.
Talent for days. (See also RRHoF playing “while my guitar gently weeps”)
Second vote would be Trent Reznor or Danny Elfman
- Plus the moment he made it rain during his Superbowl show whilst playing purple rain.
  I don't care what anyone says, it rained because of prince.
  
  Don’t care if it is apocryphal but when it started raining, he said “make it rain harder. “
  Yes. He did make it rain that day.

- Bullshit Logic. We also don't have 1000 Da Vincis, 10.000 Jesuses and 100.000 Moseses.
  
  Now imagining a Pharaoh with an unstoppable army of Mosi.

Hans Zimmer? If not in pure skill then in name recognition.

King Gizzard. They love weird-ass time signatures (look up the ridiculousness that is Crumbling Castle for an example), polyrhythms, unconventional tuning, and such. They hop from one genre to another, they probably have one of the highest album-to-year ratios in music (not including live and demo albums), sometimes they're serious, sometimes they're silly, sometimes they're silly-serious. The biggest blow to them however, is that nothing they make is truly a "masterpiece". It all ranges from "good" to "great" but nothing they've made is really a "masterpiece". Maybe in time they'll make a true masterpiece, but nothing yet quite qualifies imo.
The other nomination I'd make is Devin Townsend. Where King Gizzard is extremely prolific but doesn't make masterpieces, Devin Townsend takes his time and makes masterpieces. Despite its silliness, Ziltoid the Omniscient is one of the best, if not the best, metal albums, period. It's an album so good that even my parents, who don't like metal, have songs they enjoy from the album. Empath is a stunning blend of metal, electronic, prog, praise & worship/gospel,^1 and god knows what else. The man just does things and they come out amazing.
^1 Afaik Devin Townsend's not a Christian, sorry to any Christian peeps hoping for good Christian music. He just incorporated that sound into the album.

I love Sufjan Stevens, but I don't see the comparison. While I really love his lyrics (one of the few I actually like them, I usually find most artist lyrics to be plain and way too cheesy), his music is very simple compared to a behemoth like Mozart.
Mozart was able to write highly complex music very fast, that went from deep themes to silly ones, and enjoyed popularity from both critics and public, which is something quite rare.
I don't which one would be the closest today. Maybe something like Williams or Ennio Morricone.

Jacob Collier

You ever seen that post about how classical music is closest to metal? Well Kerry King is our modern day Mozart.
- \M/
  Dude can definitely shred and definitely plays some complex licks. Dimebag and Randy Rhodes are definitely up there too, but then again, so are many heavy metal guitarists.
  I'm a shitty guitarist and whenever I just sit back and listen to the guitar tracks on most heavy metal albums I'm always amazed by the complexity, speed, precision and just overall sound of the tracks, especially when it comes to the solos.
- Kerry is a great player, but I think the shredder who embodied the spirit and the form of Mozart was Alexi Laiho.
  His solos were a such distinct take on the neoclassical sound

David Bowie, few have his range and talent.

This is the kind of question that makes me hate my mortality, because culture is so scattered and vast and changing so rapidly these days that it seems difficult to imagine anything "modern" lasting for hundreds more years, and we'll never actually be able to know the answer.

John Williams.

Stevens is more like Bach than like Mozart. Lots of repetition in his themes but layered and created in counterpoint like no other contemporary artist. Love that guy.

Kevin MacLeod.

Quincy Jones
Prince
David Bowie
Danny Elfman
- well since Mozart is dead, and OP wants us to name a contemporary artist, isn't it a prerequisite that the artist still be alive right now?
  Danny Elfman wins. He's a fookin' musical mad genius.
- modern?

Probably Radiohead
Or Trent Reznor

I don't know anything about surfan Stevens, why him?
- He has a huge discography, is a talented multi instrumentalist, and is very experimental with genre and song writing in general while still effectively connecting with a growing audience. I used to know only a handful of his songs and thought, good but meh. Out of curiosity about his broad appeal between people I wouldn’t expect much over lap from, I dove into his discography and it’s something really special.
  
  Okay, very cool. Thanks, he sounds worth looking into

I'm learning lots of good music here, but I was really hoping Surfan Stevens was a surf-rock cover artist of Sufjan Stevens and Cat Stevens.

If you are going to compare you should add the context of each, and by adding the context Mozart was a genius and cannot be compared.

Squarepusher cones to mind

I would say David Gilmour. Pink Floyd music comes to mind for having some pretty symphonic sounds.

Ramin Djawadi no contest.

Ben Folds. He's got classical, jazz and rock chops, with a full helping of the wit and mischief in his lyrics.
- Those that like him, like him a lot. The rest of us will walk over fields of lava to hit the skip button.

Dwayne Rudolph Goettel (Skinny Puppy) Peter Christopherson (Psychic TV, Coil, Throbbing Gristle)
If we change this question to generational, instead of "modern times", those two would fit into Gen X.
Richard Wright (Pink Floyd) Ray Manzarek (Doors) Elton John
For the "Boomers".
Tori Amos Trent Reznor Atticus Ross
For the Millenials.
I'm sure there's many more from those 3 generations. But they have my vote.

I'm going to go with Steven Wilson for this. Mostly because he and Mozart have an undeniable talent, many of their fans consider them to be some type of visionary savant, and despite the broad agreement toward that perspective I still find both of their outputs to be broadly incredibly dull.

Love Sufjan. He has a Mozart mind in his own right.
If Mozart was raised with an accordion and looney tunes he might Weird Mo, if he had parents like Carrie and Lowell he might be giving LGBTQ+ and Christian Conservatives a Christmas album to agree on.
Trying to compare a Mozart of our times to the original is like comparing an apple to the tree it grew from. There are obvious similarities but fundamentally are just different things of different times.

Controversial, but Muse is up there in the great composers list.
Also Shaka Ponk, whole other story
- I wouldn't say that controversial. Muse are pretty varied in their output, The Exogenesis Symphony is fantastic, and then they also have stuff like Plug In Baby, which is amazing. Matthew Bellamy is very talented.
  
  Yeah the entirety of revolution manages to traverse several sounds and styles while maintaining a cohesive mood and feel. It and the second law were just amazing albums

ZUN.

To Mozart? I think Tony Ann fits that bill. He's not super well known yet, but he's on his way there.

Freddy Mercury and David Bowie are up there in that podium.

Alpine Universe is pretty damn good, I thought it was a band until I looked them up on Instagram and found out it was one dude that multi-tracks his voice and plays multiple instruments. I watched a few of his production videos and was amazed.

Maybe someone like John Oliva

Everyone, if everyone could live the lives they want to without starving.

The fact that Miles Davis or Duke Ellington haven't shown up yet makes me question the musical diversity of Lemmy.

Incredible Polo

Jack Antonoff has some incredible talent. He's written and produced a lot of iconic pop music.

Well, Mozart was a composer, so I don't know what parallels you're drawing from to compare hin to Weird Al or Surfan [sic] Stevens. If we're talking strictly in terms of best living musicians, Joanna Newsom is probably the best songwriter of the past fifty years, and in my opinion, the second place isn't even close.

Louis Cole has a great understanding of music structure and plays around with it very well

Justin Timberlake has dropped hit after hit for almost 30 years and hasn't had any real controversies along the way.
- Tanking Janet Jackson's career and slut-shaming Britney. Both were accepted behaviors at the time, but IMO that just makes it worse, he never even had to really account for it.

No planet on which Sufjan Stevens is a Mozart.
Uncontroversial:
Radiohead
David Bowie
Daft punk
Controversial:
Kanye
Terrible person, but then again that wasn't the question.