A bit of source manager maybe

include/d/snd/d_snd_source.h

@@ -78,8 +78,8 @@ private:
     // at 0x00: dSoundSourceIf_c vtable
     // at 0x04: dSnd3DActor_c sub-object
     // at 0x58: thunk-vtable
-    /* 0xE8 */ u8 field_0xE8[0xF0 - 0xE8];
 
+    /* 0xE8 */ nw4r::ut::Node mMgrLink;
     /* 0x0F0 */ UNKWORD field_0x0F0;
     /* 0x0F4 */ UNKWORD field_0x0F4;
     /* 0x0F8 */ dAcBase_c *mpPlayer;

include/d/snd/d_snd_source_group.h

@@ -21,6 +21,7 @@ class dSoundSource_c;
 class dSndSourceGroup_c {
 public:
     dSndSourceGroup_c();
+    dSndSourceGroup_c(u32, const char*, u32, u32);
     ~dSndSourceGroup_c();
 
     void registerSource(dSoundSource_c *);
@@ -42,8 +43,8 @@ private:
     void resetSoundSourceParam();
     void clearList();
 
-    /* 0x00 */ nw4r::ut::Node mNode;
-    /* 0x08 */ u8 _0x08[0x10 - 0x08];
+    /* 0x00 */ nw4r::ut::Node mNode1;
+    /* 0x08 */ nw4r::ut::Node mNode2;
     /* 0x10 */ UNKWORD field_0x10;
     /* 0x14 */ UNKWORD field_0x14;
     /* 0x18 */ UNKWORD field_0x18;

include/d/snd/d_snd_source_mgr.h

@@ -0,0 +1,64 @@
+#ifndef D_SND_SOURCE_MGR_H
+#define D_SND_SOURCE_MGR_H
+
+#include "d/snd/d_snd_source.h"
+#include "d/snd/d_snd_source_group.h"
+#include "d/snd/d_snd_util.h"
+#include "nw4r/ut/ut_list.h"
+
+SND_DISPOSER_FORWARD_DECL(dSndSourceMgr_c);
+
+// 0 - "" - Link
+// ActorLink::initModels
+// 0x2C - NpcKenT
+// 0x20 - Door, TBox, CharE (Chair), Tubo
+// 0x35 - TgSound
+// 0x2D - PyBird
+// 0x22 - Bamboo
+// 0x23 - Item
+
+// 0x19 - Nusi*, BKr, BBs
+// 0x1A - MgRArm, MgLArm
+// 0x1B - Mgtail
+
+class dSndSourceMgr_c {
+    SND_DISPOSER_MEMBERS(dSndSourceMgr_c);
+
+    static const u32 NUM_GROUPS = 128;
+
+public:
+    dSndSourceMgr_c();
+
+    void playFlowSound(u32 id);
+
+private:
+    /* 0x0010 */ u8 field_0x0010;
+    /* 0x0011 */ u8 field_0x0011;
+    /* 0x0012 */ u8 field_0x0012;
+    /* 0x0013 */ u8 field_0x0013;
+
+    /* 0x0014 */ dSndSourceGroup_c *mpDefaultGroup;
+    /* 0x0018 */ nw4r::ut::List mGroupList1;
+    /* 0x0024 */ nw4r::ut::List mGroupList2;
+    /* 0x0030 */ nw4r::ut::List mGroupList3;
+    /* 0x003C */ dSndSourceGroup_c mGroups[NUM_GROUPS];
+
+    // Not sure what these are for
+    /* 0x383C */ nw4r::ut::List mSourceList1; // node offset 0xE8, probably into dSoundSource::mMgrLink
+    /* 0x3848 */ nw4r::ut::List field_0x3848; // node offset 0x15C, possibly a subset of source types
+    /* 0x3854 */ nw4r::ut::List field_0x3854; // node offset 0x160
+
+    /* 0x3860 */ UNKWORD field_0x3860;
+    /* 0x3864 */ UNKWORD field_0x3864;
+    /* 0x3868 */ UNKWORD field_0x3868;
+    /* 0x386C */ f32 field_0x386C;
+
+    /* 0x3870 */ dSoundSource_c *mpPlayerSource;
+    /* 0x3874 */ dSoundSource_c *mpFiTalkSource;
+    /* 0x3878 */ dSoundSource_c *field_0x3878;
+    /* 0x387C */ dSoundSource_c *field_0x387C;
+    /* 0x3880 */ dSoundSource_c *field_0x3880; // fi singing related?
+    /* 0x3884 */ dSoundSource_c *field_0x3884;
+};
+
+#endif

include/toBeSorted/music_mgrs.h

@@ -3,6 +3,7 @@
 
 #include "common.h"
 #include "d/snd/d_snd_player_mgr.h"
+#include "d/snd/d_snd_source_mgr.h"
 
 class dSndPlayerMgr_c;
 class dSndSound_c;
@@ -29,26 +30,8 @@ extern "C" bool fn_80364DA0(void *);
 extern "C" void fn_80365020(void *);
 extern "C" void fn_80364D00(void *, s32);
 
-// ENEMY_BGM_RELATED_MGR -> dSndSourceMgr_c
-// 0x3870 = player sound source
-// 0x3874 = Fi
-
-// 0 - "" - Link
-// ActorLink::initModels
-// 0x2C - NpcKenT
-// 0x20 - Door, TBox, CharE (Chair), Tubo
-// 0x35 - TgSound
-// 0x2D - PyBird
-// 0x22 - Bamboo
-// 0x23 - Item
-
-// 0x19 - Nusi*, BKr, BBs
-// 0x1A - MgRArm, MgLArm
-// 0x1B - Mgtail
-extern "C" void *ENEMY_BGM_RELATED_MGR;
-extern "C" void fn_80384570(void *, bool);
-extern "C" void fn_803858D0(void *);
-
+#define ENEMY_BGM_RELATED_MGR (dSndSourceMgr_c::GetInstance())
+extern "C" void fn_80384570(dSndSourceMgr_c *, bool);
 
 // This one has a SoundActor that actually plays the BGM_ music tracks,
 // including the battle BGM track.