Arranging an album from beginning to end

How many times have you started singing the next song on the album after hearing a song?

There is an art to how songs fit together and a good album has a flow from beginning to end.  Albums that are composed with a flow from beginning to end are a work of art. I can honestly say those are the albums that I remember and listen to regularly. There is a glue that needs to be present when you're putting songs together for an album. Making a masterpiece is something that takes time and patience to achieve.

I had an interesting conversation with a client about how to arrange songs on his album. The first song on an album is so important. The first song sets the mood for the album.

What is the most important part of an album? Is it a collection of songs or singles? Does a good album have a flow from song to song or from beginning to end?