0x0000 - 0x04FF Song and channel configuration
0x0500 - 0x1500 Echo Buffer
0x1500 - 0x56E1 Main Engine and SFX libraries and common song note data
   SFX Libraries
   0x2AED - 0x3153 SFX Library1
   0x39B3 - 0x4701 SFX Library2
   0x4E8F - 0x530D SFX Library3
   Common Song Note Data
   0x530E - 0x546D Samus appear (Loading from save theme)
   0x546E - 0x5568 Item fanfare
   0x5569 - 0x5696 Elevator
   0x5697 - 0x56E1 Hall Before Statues
0x56E2 - 0x57FF Free
0x5800 - 0x5807 Note sound length percents
0x5808 - 0x5817 Note volume percents
0x581E - 0x58xx Song track start pointers (depends on number of tracks in song collection)
1 track: 0x5829
2 track: 0x582B
0x58xx - 0x6BFF Note Data
0x6C00 - 0x6CFF Instrument table
0x6D00 - 0x6DFF Sample Table
0x6E00 - 0xB515 Common Loaded Instruments
0xB516 - 0xFFFF Per song loaded instruments

(Common songs and instruments intact)

0x0000 - 0x04FF Song and channel configuration
0x0500 - 0x14F6 Common Loaded Instruments (Samples 00, 01, 02 and 03)
0x14F7 - 0x14FF Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x1500 - 0x56E1 Main Engine and sfx libraries
   SFX Libraries
   0x2AED - 0x3153 SFX Library1 
   0x39B3 - 0x4701 SFX Library2
   0x4E8F - 0x530D SFX Library3
   Common Song Note Data
   0x530E - 0x546D Samus appear (Loading from save theme)
   0x546E - 0x5568 Item fanfare
   0x5569 - 0x5696 Elevator
   0x5697 - 0x56E1 Hall Before Statues
0x56E2 - 0x57F0 Common Loaded Instruments (Samples 0C, 0D)
0x57F1 - 0x57FF Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x5800 - 0x5807 Note sound length percents
0x5808 - 0x5817 Note volume percents
0x5818 - 0x581D Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x581E - 0x583F Song track start pointers
0x5840 - 0x6BDE Common Loaded Instruments (Samples 0A/0B, 08, 11/12)
0x6BDF - 0x6BFF Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x6C00 - 0x6CFF Instrument table
0x6D00 - 0x6DA8 Sample Table
0x6DA9 - 0x8D16 Common Loaded Instruments (Samples 04, 05, 06, 07, 09, 0E, 0F, 10, 13, 14, 15)
0x8D17 - 0x8EFF Free (either note data or sample data)
0x8F00 - 0xFF00 Shared variable length echo buffer, note data and sample data.
0xFF01 - 0xFFFF Free (either note data or sample data)

(No common songs, minimal common loaded instruments)

0x0000 - 0x04FF Song and channel configuration
0x0500 - 0x14F6 Common Loaded Instruments (Samples 00, 01, 02 and 03)
0x14F7 - 0x14FF Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x1500 - 0x56E1 Main Engine and sfx libraries
   SFX Libraries
   0x2AED - 0x3153 SFX Library1 
   0x39B3 - 0x4701 SFX Library2
   0x4E8F - 0x5300 SFX Library3 (Lib 3 must have at least 0xD bytes of optimization done)
0x5301 - 0x57FF Common Loaded Instruments (Sample 04)
0x5800 - 0x5807 Note sound length percents
0x5808 - 0x5817 Note volume percents
0x5818 - 0x581D Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x581E - 0x583F Song track start pointers
0x5840 - 0x6BF9 Common Loaded Instruments (Samples 05, 06, 07, 08, 09, 0C, 0D, 10)
0x6BFA - 0x6BFF Free (Probably best used as pointers to sfx data if editing the sfx libraries to be more compact)
0x6C00 - 0x6CFF Instrument table
0x6D00 - 0x6DA8 Sample Table
0x6DA9 - 0x7BA7 (Samples 0E, 0F, 11, 12, 13, 14, 15)
0x7BA8 - 0x7EFF Free (either note data or sample data)
0x7F00 - 0xFF00 Shared variable length echo buffer, note data and sample data.
0xFF01 - 0xFFFF Free (either note data or sample data)