I had some stuff written that I didn't put on the last album, because they were just really pop songs. They felt like anachronisms on the last record. So I saved all these little pop songs."
The speaker is explaining their decision to hold onto pop songs they wrote but didn't include on their previous album because they felt the songs were too "pop" and didn't fit with the overall style of the record. They are now considering using these songs in a future release.