Streaming issues iphone 4

[JamSlamBamm]

Sup fellow music lovers I'm having a problem with my streaming on my iphone 4 running iOS 7.4 or something I dunno canny be arsed to check. But the problem starts after I've opened the app and selected the song I want. It plays smoothly when I'm on the app but wen I change over to messenger or safari or even text messages it cuts for like 1-3 seconds then resumes which isn't major but I'll be playing a song bass drop comes up think ima hit it and then boom cuts then resumes. Missed so many decent drops and just curious if any one of you guys have had this problem? I pay £9.95 a month for premium but the service I'm getting isn't premium, my streaming quality is on normal so is download, checked all my background apps on my iphone and nothing has sorted it. Royal pain in the **bleep**. For example I'll play a song go to messenger it's fine but soon as I start typing it stutters like it's struggling to play. Any ideas ladies and gentlemen? Anything would be appreciated ✌️💯 peace