Talk to Isabelle at the counter in the Town Hall and choose "problematic citizens." This will allow you to choose the neighbor, then give you some options. The options are:
"His/her language is rude." This resets their greeting and catchphrase.
"His/her clothes are wrong." This randomly changes their clothes.
"He/she has a naughty letter." I'm not sure what this option does. Deletes the letter I guess.
Also, when you put things up for sale at Re-Tail, your neighbors will occasionally come in to the shop when you're there. They will randomly select an item which will be announced by the alert sound and surprise lines over their head. You can influence them to purchase what they're looking at. If you have clothes in Re-Tail, that's another possible way for them to change their clothes.
After going through Reggie's house, documenting all the items that he owned that I also had in my catalog, comparing the prices and doing the math, I've found out that ordering an item through the Happy Home Showcase is 1.2x more expensive.
Here are a few of the items for comparison:
Item Catalog Price HHS Price
Modern Wood Stool 1,480 1,776
Dartboard 1,520 1,824
Exotic Screen 2,250 2,700
In addition, you can only order up to 5 items in a single day. I was able to find additional sources confirming this number here and here, though it's still not stated on Nintendo's official website (which is par for the course for a lot of this game).
So if you want to order something, you'll have to pay 20% more bells, but it may be worth it for those items that you really want and/or haven't been able to find yet. Standard limitations on rare items apply here, so anything you can't order normally through your own Catalog, like the Nintendo set, Gyroids, HHA rewards, etc., you also cannot order through the HHS.
Best Answer
You can receive music by going to Club LOL once it is open on Saturday evenings after 8pm. Once there, you can talk to K.K. Slider and depending on what you decide to do, you can either receive a random song or a song of your choice to take home.
In your inventory, songs look like a yellow music note. Interact with your music player with it in your inventory and you'll be able to load the song into it to play and eject it later if you decide to do something with it (like hang it on your wall or make it into a music box).