Database Users

[Q] How can I access playlist created by music app and call the music app to play it?

Hi, I don't know if it is the right place to ask this question but I need some help.
I am writing an android app, and I want to access the playlist created by android default music app.
In my app, the user should be able to browse the playlist and select any playlist to play.
So basically I want to know how to access it and when user selects any playlist, how to pass it to default music app to play it in background.
Is it something to do with ContentProvider or mediastore?? I really don't know how to access data on other apps.
Thank you so much!

[Q] Unremovable Google Music Notification

Hi,
Since i saw "Wear Music Controller" app, I was wondering if is it possible to make Google Music notification persistent (no need for it to be persistent on phone, just on watch, but anything will suit me). You might say: "Well, use this app then?" - No. Becuase it makes 2 notifications which are annoying (one from app, and one "stock" from google). Im also not going to change music player. I can do whatever it takes. Nexus 5 rooted, and LG G Watch rooted. So i can even "play" with some files to make it work. Any ideas?

Manage watch music

There is 1 Gig of music on my watch.
May want to delete most of the music but how do you manage the songs on the watch?

Stop Google Play Music from deleting cached music

Is there anyway to stop this from happening? Unless you pin music, eventually old music gets deleted even when there's ton of space on the phone.

If you have the actual files just download them to your phone and they will always be there.
Otherwise:
1. There is an option if you go into google play music settings to auto-download music
2. If you go into the music library, click on a playlist and you'll see a download icon in between the album covers and the actual song list

Whitelist Google Play Music to avoid battery optimization?

The other day I was trying to listen to music while my hands were full and Google Play Music would periodically stop. I understand that by default the 6T has all apps set to battery optimize, and I have successfully regained my Hangouts notifications by changing the setting for that app. However, when I look at the list of apps in the battery settings I don't see Music, Play Music, or Google Play Music, so I can't change it. Does anyone have a work around?
I'm not rooted but I did unlock the bootloader so I can do that if I need to.
Thanks!