diff --git a/platypush/backend/midi.py b/platypush/backend/midi.py
index e4f08630..61f182e4 100644
--- a/platypush/backend/midi.py
+++ b/platypush/backend/midi.py
@@ -24,13 +24,19 @@ class MidiBackend(Backend):
     def __init__(self, device_name=None, port_number=None,
                  midi_throttle_time=None, *args, **kwargs):
         """
-        :param device_name: Name of the MIDI device.  *N.B.* either `device_name` or `port_number` must be set
+        :param device_name: Name of the MIDI device.  *N.B.* either
+            `device_name` or `port_number` must be set.
+            Use :method:`platypush.plugins.midi.query_ports` to get the
+            available ports indices and names
         :type device_name: str
 
         :param port_number: MIDI port number
         :type port_number: int
 
-        :param midi_throttle_time: If set, the MIDI events will be throttled - max one per selected time frame (in seconds). Set this parameter if you want to synchronize MIDI events with plugins that normally operate with a lower throughput.
+        :param midi_throttle_time: If set, the MIDI events will be throttled -
+            max one per selected time frame (in seconds). Set this parameter if
+            you want to synchronize MIDI events with plugins that normally
+            operate with a lower throughput.
         :type midi_throttle_time: int
         """
 
diff --git a/platypush/plugins/midi.py b/platypush/plugins/midi.py
index de0e35a1..ab9bba8a 100644
--- a/platypush/plugins/midi.py
+++ b/platypush/plugins/midi.py
@@ -120,5 +120,20 @@ class MidiPlugin(Plugin):
             self.release_note(note)
 
 
+    @action
+    def query_ports(self):
+        """
+        :returns: dict: A list of the available MIDI ports with index and name
+        """
+
+        in_ports = rtmidi.MidiIn().get_ports()
+        out_ports = rtmidi.MidiOut().get_ports()
+
+        return {
+            'in': { i: port for i, port in enumerate(in_ports) },
+            'out': { i: port for i, port in enumerate(out_ports) },
+        }
+
+
 # vim:sw=4:ts=4:et:
 
diff --git a/platypush/plugins/sound/core.py b/platypush/plugins/sound/core.py
index fba2302d..bbca23c0 100644
--- a/platypush/plugins/sound/core.py
+++ b/platypush/plugins/sound/core.py
@@ -214,6 +214,15 @@ class Mix(object):
         self._sounds.append(Sound.build(sound))
 
 
+    def remove(self, sound_index):
+        if sound_index >= len(self._sounds):
+            self.logger.error('No such sound index: {} in mix {}'.format(
+                sound_index, list(self)))
+            return
+
+        self._sounds.pop(sound_index)
+
+
     def get_wave(self, t_start=0., t_end=0., normalize_range=(-1.0, 1.0),
                  on_clip='scale', samplerate=Sound._DEFAULT_SAMPLERATE):
         """
diff --git a/platypush/plugins/sound/plugin.py b/platypush/plugins/sound/plugin.py
index 35fb9e4e..2d3d0bd9 100644
--- a/platypush/plugins/sound/plugin.py
+++ b/platypush/plugins/sound/plugin.py
@@ -325,7 +325,7 @@ class SoundPlugin(Plugin):
                             if duration is not None else t+blocktime
 
                         data = mix.get_wave(t_start=t, t_end=next_t,
-                                              samplerate=samplerate)
+                                            samplerate=samplerate)
                         t = next_t
 
                         if duration is not None and t >= duration:
@@ -706,6 +706,47 @@ class SoundPlugin(Plugin):
         self.logger.info('Recording paused state toggled')
         self.recording_paused_changed.set()
 
+    @action
+    def release(self, stream, index=None, midi_note=None, frequency=None):
+        """
+        Remove a sound from an active stream, either by sound index (use
+            :method:`platypush.sound.plugin.SoundPlugin.query_streams` to get
+            the sounds playing on the active streams), midi_note, frequency
+            or absolute file path.
+
+        :param stream: Stream index
+        :type stream: int
+
+        :param index: Sound index
+        :type index: int
+
+        :param midi_note: MIDI note
+        :type midi_note: int
+
+        :param frequency: Sound frequency
+        :type frequency: float
+        """
+
+        if index is None and midi_note is None and frequency is None:
+            raise RuntimeError('Please specify either a sound index, ' +
+                               'midi_note or frequency to release')
+
+        mix = self.stream_mixes.get(stream)
+        if not mix:
+            raise RuntimeError('No such stream: {}'.format(stream))
+
+        for i, sound in enumerate(mix):
+            if (index is not None and i == index) or \
+                    (midi_note is not None
+                     and sound.get('midi_note') == midi_note) or \
+                    (frequency is not None
+                     and sound.get('frequency') == frequency):
+                if len(list(mix)) == 1:
+                    # Last sound in the mix
+                    self.stop_playback([stream])
+                else:
+                    mix.remove(i)
+
     def _get_playback_state(self, stream_index):
         with self.playback_state_lock:
             return self.playback_state[stream_index]