Seth Godin has written frequently about using two axes of differentiation (X-Y axes) as a way to target your art. (This post lays it out with a big quote from Godin’s book This is Marketing.)
In short: if you lay out two characteristics along the X-Y axis (remember coordinate geometry?) you can think about how you want the art you make to inhabit that grid.
In this case, I’ve been thinking about difficulty of singing and joy of singing. Here, I’ve plotted those two characteristics and placed some familiar choral/vocal works and plotted where I think they should be plotted (your opinions will vary).
The work I want to write exists in the top-right quadrant, but ideally in the triangle that is closer to the joy axis than to the difficult axis. Knowing this helps me to assess music as I’m writing it. If when I’ve written something it lands somewhere else on this chart, then I need to think about it.
(For the record, I’m happy to write music that is easy to sing. I still want it to be on the joyful end of the spectrum when I do – closer to “Silent Night at Xmas” than to “School Chorals.”
Other people have different intentions to where their work should fall (perhaps, joyful and easy to sing) – or different axes they are using to assess their work. Power instead of joy, say, or social impact, or sales projections. What you choose for your axes is less important than knowing how you want your art to land on the chart.