My favorite music player app is Pulsar Music Player - Mp3 Player, Audio Player. When you click on shuffle, most music apps use an algorithm where some songs play a lot, and some songs very rarely or ever play. When you click shuffle with Pulsar it will take all the songs you have on your device, and create a random playlist, so every song will get played. I have a couple of thousand songs on my phone, and once it plays all the songs through, I just click shuffle, and it creates a totally new order. There is a free version, and a paid version. The paid version adds an equalizer. Other than that they are the same.
https://play.google.com/store/apps/details?id=com.rhmsoft.pulsar&hl=en_US