With D language it can be the music, instruments, player and the conductor all at once [1].
Fun facts, Walter the original author of D language wrote his popular Empire game in Fortran [2]. Some of the ideas that make Fortran fast is incorporated into D language design and this makes D is as easy if not easier to optimize than Fortran [1].
[1]Numeric age for D: Mir GLAS is faster than OpenBLAS and Eigen: