diff --git a/libraries/adlmidi/adlmidi.cpp b/libraries/adlmidi/adlmidi.cpp
index 12d0e68e28..69a120da90 100644
--- a/libraries/adlmidi/adlmidi.cpp
+++ b/libraries/adlmidi/adlmidi.cpp
@@ -504,9 +504,9 @@ ADLMIDI_EXPORT void adl_setLoopEnabled(ADL_MIDIPlayer *device, int loopEn)
 {
     if(!device)
         return;
-    MidiPlayer *play = GET_MIDI_PLAYER(device);
-    assert(play);
 #ifndef ADLMIDI_DISABLE_MIDI_SEQUENCER
+	MidiPlayer *play = GET_MIDI_PLAYER(device);
+	assert(play);
     play->m_sequencer.setLoopEnabled(loopEn != 0);
 #else
     ADL_UNUSED(loopEn);
diff --git a/libraries/oplsynth/OPL3.cpp b/libraries/oplsynth/OPL3.cpp
index f7bbca0af5..be1c717e62 100644
--- a/libraries/oplsynth/OPL3.cpp
+++ b/libraries/oplsynth/OPL3.cpp
@@ -45,6 +45,7 @@
 
 #include <math.h>
 #include <stdlib.h>
+#include <string.h>
 #include <limits>
 
 #include "opl.h"
diff --git a/libraries/oplsynth/dosbox/opl.h b/libraries/oplsynth/dosbox/opl.h
index b4d7548add..eba6ee6eed 100644
--- a/libraries/oplsynth/dosbox/opl.h
+++ b/libraries/oplsynth/dosbox/opl.h
@@ -155,7 +155,6 @@ typedef struct operator_struct {
 class DBOPL : public OPLEmul
 {
 private:
-	Bitu chip_num;
 	op_type op[MAXOPERATORS];
 
 	Bits int_samplerate;
diff --git a/libraries/oplsynth/fmopl.cpp b/libraries/oplsynth/fmopl.cpp
index 3a1e94a327..353e313392 100644
--- a/libraries/oplsynth/fmopl.cpp
+++ b/libraries/oplsynth/fmopl.cpp
@@ -552,8 +552,6 @@ static const int8_t lfo_pm_table[8*8*2] = {
 };
 
 
-/* lock level of common table */
-static int num_lock = 0;
 
 /* work table */
 static signed int phase_modulation;		/* phase modulation input (SLOT 2) */
diff --git a/libraries/oplsynth/opl_mus_player.cpp b/libraries/oplsynth/opl_mus_player.cpp
index 09fff7e133..ebb39f3826 100644
--- a/libraries/oplsynth/opl_mus_player.cpp
+++ b/libraries/oplsynth/opl_mus_player.cpp
@@ -258,7 +258,6 @@ bool OPLmusicBlock::ServiceStream (void *buff, int numbytes)
 	std::lock_guard<std::mutex> lock(ChipAccess);
 	while (numsamples > 0)
 	{
-		double ticky = NextTickIn;
 		int tick_in = int(NextTickIn);
 		int samplesleft = std::min(numsamples, tick_in);
 		size_t i;
diff --git a/libraries/opnmidi/opnmidi.cpp b/libraries/opnmidi/opnmidi.cpp
index 2f35e2a05b..f3b4314a6b 100644
--- a/libraries/opnmidi/opnmidi.cpp
+++ b/libraries/opnmidi/opnmidi.cpp
@@ -361,9 +361,9 @@ OPNMIDI_EXPORT void opn2_setLoopEnabled(OPN2_MIDIPlayer *device, int loopEn)
 {
     if(!device)
         return;
-    MidiPlayer *play = GET_MIDI_PLAYER(device);
-    assert(play);
 #ifndef OPNMIDI_DISABLE_MIDI_SEQUENCER
+	MidiPlayer *play = GET_MIDI_PLAYER(device);
+	assert(play);
     play->m_sequencer.setLoopEnabled(loopEn != 0);
 #else
     ADL_UNUSED(loopEn);
diff --git a/libraries/wildmidi/gus_pat.cpp b/libraries/wildmidi/gus_pat.cpp
index e2080e24d5..fbfc579716 100644
--- a/libraries/wildmidi/gus_pat.cpp
+++ b/libraries/wildmidi/gus_pat.cpp
@@ -784,8 +784,6 @@ struct _sample * Instruments::load_gus_pat(const char *filename)
 	};
 	unsigned long int tmp_loop;
 
-	/*unused*/fix_release;
-
 	SAMPLE_CONVERT_DEBUG(__FUNCTION__); SAMPLE_CONVERT_DEBUG(filename);
 
 	if ((gus_patch = _WM_BufferFile(sfreader, filename, &gus_size)) == NULL) {
diff --git a/libraries/wildmidi/wildmidi_lib.cpp b/libraries/wildmidi/wildmidi_lib.cpp
index 4254c1f116..3401e997a2 100644
--- a/libraries/wildmidi/wildmidi_lib.cpp
+++ b/libraries/wildmidi/wildmidi_lib.cpp
@@ -1666,7 +1666,6 @@ static void do_control_data_entry_course(struct _mdi *mdi,
 
 void Renderer::do_control_channel_volume(struct _mdi *mdi, struct _event_data *data)
 {
-	struct _note *note_data = mdi->note;
 	unsigned char ch = data->channel;
 
 	mdi->channel[ch].volume = (unsigned char)data->data;
@@ -1691,7 +1690,6 @@ void Renderer::do_control_channel_pan(struct _mdi *mdi, struct _event_data *data
 
 void Renderer::do_control_channel_expression(struct _mdi *mdi, struct _event_data *data)
 {
-	struct _note *note_data = mdi->note;
 	unsigned char ch = data->channel;
 
 	mdi->channel[ch].expression = (unsigned char)data->data;
@@ -1837,7 +1835,6 @@ static void do_control_channel_sound_off(struct _mdi *mdi,
 
 void Renderer::do_control_channel_controllers_off(struct _mdi *mdi, struct _event_data *data)
 {
-	struct _note *note_data = mdi->note;
 	unsigned char ch = data->channel;
 
 	mdi->channel[ch].expression = 127;