Add logging when basic channel config is changed

src/synth/fluid_synth.c

@@ -1745,9 +1745,15 @@ fluid_synth_cc_LOCAL(fluid_synth_t *synth, int channum, int num)
                 /* reset the current basic channel before changing it */
                 fluid_synth_reset_basic_channel_LOCAL(synth, channum, chan->mode_val);
                 fluid_synth_set_basic_channel_LOCAL(synth, channum, new_mode, value);
+                FLUID_LOG(FLUID_INFO, "Successfully configured channel group, from channel %d up to including chan %d to mode 0x%X", channum, channum + value, new_mode);
                 break; /* FLUID_OK */
             }
         }
+        else
+        {
+            static const char* poly_mono_str[] = {"OMNI_OFF","OMNI_ON","POLY_OFF","POLY_ON"};
+            FLUID_LOG(FLUID_WARN, "Failed to set channel %d to %s: Operation illegal, because channel is currently no basic channel.", channum, poly_mono_str[num - OMNI_OFF]);
+        }
 
         return FLUID_FAILED;