At the bottom of the album art view you will see two icons. The first looks like two arrow lines crossed. The second is either looped arrows, or looped arrows with a "1" on it. The first icon is shuffle mode, and will play the entire album in a random order. The second icon turns on loopoing for the entire album, or just the current song (the "1")
It sounds like that's what is going on. Tap the icon to cycle through the modes.
Hold in mind this thread is kind of old (2013), so a lot of the descriptions are out of date. The following image is of iOS 8.4. I you've got an earlier version you may have only one icon that cycles between all three modes, and it may appear on different screens.
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