diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..8362a36
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,7 @@
+if type lorri &>/dev/null
+then
+  echo "direnv: using lorri"
+  eval "$(lorri direnv)"
+else
+  use nix
+fi
diff --git a/shell.nix b/shell.nix
index 7c57d3c..be19bb4 100644
--- a/shell.nix
+++ b/shell.nix
@@ -4,6 +4,8 @@ pkgs.mkShell {
   buildInputs = with pkgs; [
     gnumake
     gnuplot
+    graphviz
+    lilypond
     octaveFull
     python3
     racket