[jdavia]

You want a song book to be read easily.
When you print in two columns, if the font is large enough to be read in a dim light like in a bar, the type will be ireagularlly lineated, and sometimes harder to understand. Like the song numbers or artist name broken on two lines. This may force you to use a smaller font which may not be read as easy under such lighting conditions even if the pages are printed in Landscape.

The best compromise is to print less books that will read easily.