Java Sound: devices found when run in IntelliJ, but not in SBT

Java Sound: devices found when run in IntelliJ, but not in SBT

I'm trying to to use Java Sound API in a Scala SBT-managed project.
Here is a toy app that plays a note.
import javax.sound.midi._
object MyMain extends App {
val infos = MidiSystem.getMidiDeviceInfo()
println( "[DEBUG] midi devices found: " + infos.length )
val myMsg = new ShortMessage;
// Start playing the note Middle C (60),
// moderately loud (velocity = 93).
myMsg.setMessage(ShortMessage.NOTE_ON, 0, 60, 93);
val timeStamp = -1;
val rcvr : Receiver = MidiSystem.getReceiver();
rcvr.send(myMsg, timeStamp);
readChar() // give time to play note
}
When I execute run in SBT, I get the
javax.sound.midi.MidiUnavailableException because infos.length returns 0.
That said, when I run the app in IntelliJ, two devices are found and the
note plays just fine.
What does SBT need to know to make it run? Is there something which needs
to be added to the classpath? I noticed that IntelliJ attaches a whole
bunch of jars to the execution command (however, removing those of the
jars that come from jdk/jre/lib/ had no effect, while the others are scala
related or IntelliJ related).