Mr. Blake derived a simple melody by playing a few dozen digits of pi using a C-major scale, with 3, 1, 4, 1, 5, 9 translated to the notes E, C, F, C, G, D and so on.

WSJ: We Can All Have a Slice of Pi | Postmodern Times by Eric Felten

What is interesting is that the conversions of biomass (e.g. switchgrass and salicornia) to synthetic diesel using Fischer-Tropsch (F-T.) and coal to liquids with F.

FORBES: Land Use Changes Are Main Factor In Carbon Emissions From Biofuels