     Serial.println(F("SD failed, or not present"));
     while (1);  // don't do anything more
   }
-  Serial.println("SD initialized");
-
-  File root = SD.open("/");
+  Serial.println(F("SD initialized"));
+
+  File root = SD.open(F("/"));
   while (true) {
     File entry = root.openNextFile();
     if (!entry) break;
     Serial.print(entry.name());
     if (entry.isDirectory()) {
-      Serial.println("/");
+      Serial.println(F("/"));
     } else {
-      Serial.print("\t\t");
+      Serial.print(F("\t\t"));
       Serial.println(entry.size(), DEC);
     }
   }


  Serial.begin(14400);
  while (!Serial && millis() < nextIdleTick + 2000);
  Serial.println("MusicBox setup");

  initializeCard();
  initializePlayer();

  // No keys when paused
  if (state == PLAY_PAUSED) {
    // nop
    Serial.println(F("Still paused"));

  // Same key pressed again
  } else if (state == PLAY_SELECTED && playingAlbum == index) {
