The colors used reminded me of pvc pipes, but I don’t think that is what is meant by Eleven Pipers in the song…

Use the larger needles to both cast on and bind off this sideways knit scarf, to prevent curling of the edges.

The color changes will alternate knit and purl rows, pay attention to how the scarf looks on the right side and work the row so that the color change is “clean” on the right side.