Adafruit VS1053 Codec + MicroSD Breakout - MP3/WAV/MIDI/OGG Play + Record - v4

Wow, playing at 30,000's not going to work. The page says right at the top:

Waveforms can use up so much CPU that they make render Espruino unresponsive if you create a repeating Waveform with a frequency that is too high (above 10kHz input or 20kHz output).

Did you try literally just using the example as-is first? :)