Here are the data structures with brief descriptions:
  _fluid_gen_t | SoundFont generator structure |
| _fluid_mod_t | Modulator structure |
| _fluid_preset_t | Virtual SoundFont preset |
| _fluid_ringbuffer_t | Lockless event queue instance |
| _fluid_rvoice_buffers_t | Rvoice mixer-related parameters |
| _fluid_rvoice_dsp_t | Rvoice parameters needed for dsp interpolation |
| _fluid_rvoice_envlfo_t | Rvoice ticks-based parameters These parameters must be updated even if the voice is currently quiet |
| _fluid_rvoice_eventhandler_t | Bridge between the renderer thread and the midi state thread |
| _fluid_rvoice_t | Parameters needed to synthesize a voice |
| _fluid_sample_t | Virtual SoundFont sample |
| _fluid_sfloader_t | SoundFont loader structure |
| _fluid_sfont_info_t | Structure used for sfont_info field in fluid_synth_t for each loaded SoundFont with the SoundFont instance and additional fields |
| _fluid_sfont_t | Virtual SoundFont instance structure |
| _fluid_synth_channel_info_t | Channel information structure for fluid_synth_get_channel_info() |
| fluid_cmd_t | Shell command information structure |
| fluid_event_channel_int_t | Structure for an integer parameter sent to a MIDI channel (bank or SoundFont ID for example) |
| fluid_event_gen_t | SoundFont generator set event structure |
| fluid_event_preset_t | Preset channel assignment event structure |
| fluid_event_queue_elem_t | Event queue element structure |
| fluid_event_repl_tuning_t | Tuning replacement event structure |
| fluid_event_set_tuning_t | Tuning assignment event structure |
| fluid_event_unref_tuning_t | Tuning unref event structure |
 fluid_playlist_item | Fluid_playlist_item Used as the `data' elements of the fluid_player.playlist |
