Singles Not Appearing for Album Recording?

"Albums should contain at least 6, and at most 12 songs. Albums should contain at least 1 released single by your band. You can't select singles, which have already been included in another album."

I was planning on recording an album, however the only singles that appear as an option are the ones that have already been released. I have two songs that have already been recorded, but not released that do not appear. As well as one unrecorded song—however I'm assuming they would have to be recorded in order to appear on the album list—so that makes sense. The band has not recorded/released any other albums, so the songs have not been used.

The wording 'at least 1 released single' makes it seem like they don't all have to be released, so I'm confused as to why the unreleased, recorded songs are not appearing.
all singles have to be released to be used in an album. but you can record an album with only one released single, but it will take 5 additional days to record (to write the other 5 songs needed for a 6 song album). if you use 6 released singles the album will be recorded in 1 day.