Reddit mentions of 2017 LG 4K Ultra HD 3D Blu-ray Player with Remote Control, HDR Compatibility, Upconvert DVDs, Ethernet, HDMI, USB Port, Black

For $300 to $400 for music and possible use with a TV, an AV receiver and a pair of bookshelf speakers will be much better.

Then you also have HDMI switching as well as onboard crossovers and the option of adding more speakers for surround sound later if you want to. Just as easy to setup as a system in a box.

Receivers:

• Denon AVR-S540 $150 refurbished 5.2, one year factory warranty, with HDMI 2.0B and HDCP 2.2 for 4K video switching.
  
• Denon AVR-S640 $200 refurbished 5.2 adds Audyssey MultEQ room correction / speaker calibration.
  
• Denon AVRX1400 $250 refurbished 7.2/5.2.2, adds the excellent Audyssey MultEQ XT, or new half price for $300 with a 3 year factory warranty.
  
  For a CD player add one for $100+ or for a low budget a $35 DVD player or a $65+ Blu-ray player or a Ultra 4K player for $160+. Also very easy to find a used CD or DVD player at thrift shops for $10.
  
  Speakers:
  
  Bookshelf $100 to $250:
  
  
• Airmotiv B1 Pair $230, great deal and recently reduced from $300.
  
• Big Infinity Reference R162 $175 refurbished.
  
• Wavecrest Audio HVL-1, and order on sale here at Ascend $80 each + shipping.
  
• Polk S15 $185.
  
• BIC Venturi DV62si 6-1/2" 2-Way Bookshelf Speaker Pair $120.
  
• Polk Audio Monitor 40 $100
  
  Towers:
  
  
• BOSTON ACOUSTICS A250 5.25" $225
  
• Pioneer-SP-FS52 $200
  
  Speaker wire:
  
  
• Pure copper oxygen free 16 Guage and self adjusting wire strippers or basic.
  
• Or get pre-cut and terminated with Banana Plugs Micca. Or KK for the Denon 540.
  
  Home Theater Guides:
  
  r/HTBuyingGuides FAQ • How to Set Up a Basic Home Theater System - Lifewire • How to Set Up Your Home Theater Receiver • Speaker Placement for Home Theater
  
  Home Audio Guides:
  
  Intro to home stereo systems • Zeos Tutorials, Diagrams and Videos • r/Audiophile Getting Started • Beginner's Guide to Home Audio • AverageJoeAudiophile's Guides • Speaker Placement for Stereo Music Listening.

LPT: spend a couple of extra bucks (or maybe save a few) and get a 4K player (not just "4K upscaling;" that's a trap). Sure it's overpowered now, but you'll be able to use it for another couple of decades and you'll have it in-hand when you see a cheap 4K TV you want in a few years (they're bonkers cheap now, compared with just a couple of years ago).

$15 more: https://www.amazon.com/LG-Blu-ray-Compatibility-Upconvert-Ethernet/dp/B077KXYTGG

$20 less (it's a refurb, but hey, it's new to you): https://www.amazon.com/Sanyo-Ultra-Blu-Ray-Player/dp/B07931LR92
(I just noticed they say this one doesn't have Netflix and Amazon streaming apps; which is kind of a downer if you have no other source for those, like built into your TV, or on a Chromecast/Roku/Fire/AppleTV dongle...)