diff --git a/gnu/local.mk b/gnu/local.mk
index 6f213b2e7f..8a20f54e9f 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -2072,6 +2072,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/yggdrasil-extra-config.patch	\
   %D%/packages/patches/zig-do-not-link-against-librt.patch	\
   %D%/packages/patches/zig-use-system-paths.patch		\
+  %D%/packages/patches/zynaddsubfx-3.0.6-system-rtosc.patch	\
   %D%/packages/patches/zsh-egrep-failing-test.patch
 
 MISC_DISTRO_FILES =				\
diff --git a/gnu/packages/music.scm b/gnu/packages/music.scm
index 446580dc52..ec19318b6f 100644
--- a/gnu/packages/music.scm
+++ b/gnu/packages/music.scm
@@ -157,6 +157,7 @@ (define-module (gnu packages music)
   #:use-module (gnu packages man)
   #:use-module (gnu packages mp3)
   #:use-module (gnu packages mpd)
+  #:use-module (gnu packages mruby-xyz)
   #:use-module (gnu packages ncurses)
   #:use-module (gnu packages netpbm)
   #:use-module (gnu packages pcre)
@@ -3175,10 +3176,18 @@ (define-public zynaddsubfx
                     version "/zynaddsubfx-" version ".tar.bz2"))
               (sha256
                (base32
-                "1bkirvcg0lz1i7ypnz3dyh218yhrqpnijxs8n3wlgwbcixvn1lfb"))))
+                "1bkirvcg0lz1i7ypnz3dyh218yhrqpnijxs8n3wlgwbcixvn1lfb"))
+              (patches
+               (search-patches
+                "zynaddsubfx-3.0.6-system-rtosc.patch"))))
     (build-system cmake-build-system)
     (arguments
-     `(#:phases
+     `(#:configure-flags `("-DGuiModule=zest"
+                         ,(string-append "-DZYN_DATADIR="
+                                         (assoc-ref %outputs "out")
+                                         "/share/zynaddsubfx")
+                         "-DZYN_SYSTEM_RTOSC=ON")
+       #:phases
        (modify-phases %standard-phases
          ;; Move SSE compiler optimization flags from generic target to
          ;; athlon64 and core2 targets, because otherwise the build would fail
@@ -3188,10 +3197,19 @@ (define-public zynaddsubfx
             (substitute* "src/CMakeLists.txt"
               (("-msse -msse2 -mfpmath=sse") "")
               (("-march=(athlon64|core2)" flag)
-               (string-append flag " -msse -msse2 -mfpmath=sse"))))))))
+               (string-append flag " -msse -msse2 -mfpmath=sse")))))
+         (add-after 'unpack 'patch-paths
+           (lambda* (#:key inputs #:allow-other-keys)
+             (substitute* "src/main.cpp"
+               (("\\./zyn-fusion")
+                (search-input-file inputs "/bin/zyn-fusion")))
+             (substitute* "src/Plugin/ZynAddSubFX/ZynAddSubFX-UI-Zest.cpp"
+               (("\\./libzest\\.so")
+                (search-input-file inputs "/lib/libzest.so"))))))))
     (inputs
      (list liblo
-           ntk
+           rtosc
+           mruby-zest
            mesa
            alsa-lib
            jack-1
@@ -3203,7 +3221,7 @@ (define-public zynaddsubfx
     (native-inputs
      (list pkg-config
            ruby))
-    (home-page "https://zynaddsubfx.sf.net/")
+    (home-page "https://zynaddsubfx.sourceforge.io/")
     (synopsis "Software synthesizer")
     (description
      "ZynAddSubFX is a feature heavy realtime software synthesizer.  It offers
diff --git a/gnu/packages/patches/zynaddsubfx-3.0.6-system-rtosc.patch b/gnu/packages/patches/zynaddsubfx-3.0.6-system-rtosc.patch
new file mode 100644
index 0000000000..edf22c389b
--- /dev/null
+++ b/gnu/packages/patches/zynaddsubfx-3.0.6-system-rtosc.patch
@@ -0,0 +1,106 @@
+Adding the option ZYN_SYSTEM_RTOSC to let the use of the system provided RtOsc
+instead of using the bundled one.
+
+--- a/CMakeLists.txt	2022-01-22 02:46:21.000000000 +0100
++++ b/CMakeLists.txt	2023-05-03 23:17:58.411667901 +0200
+@@ -10,24 +10,34 @@
+ add_definitions(-DZYN_DATADIR="${ZYN_DATADIR}")
+ endif()
+ 
++option(ZYN_SYSTEM_RTOSC "Use system provided librtosc and librtosc-cpp" OFF)
++
+ #Include RTOSC
+-if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/rtosc/CMakeLists.txt")
+-    message(STATUS "RTOSC NOT FOUND")
+-    message(STATUS "Attempting to checkout submodule")
+-    find_package(Git REQUIRED)
+-    execute_process(COMMAND git submodule update --init --recursive)
++if(ZYN_SYSTEM_RTOSC)
++    include(FindPkgConfig)
++    pkg_check_modules(RTOSC REQUIRED librtosc)
++    pkg_check_modules(RTOSC_CPP REQUIRED librtosc-cpp)
++    include_directories(${RTOSC_INCLUDE_DIR})
++    message(STATUS "Found system provided librtosc and librtosc-cpp...")
++else()
+     if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/rtosc/CMakeLists.txt")
+-        message(FATAL_ERROR "FAILED TO CHECKOUT RTOSC\n"
+-        "please check file permissions and your network")
++        message(STATUS "RTOSC NOT FOUND")
++        message(STATUS "Attempting to checkout submodule")
++        find_package(Git REQUIRED)
++        execute_process(COMMAND git submodule update --init --recursive)
++        if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/rtosc/CMakeLists.txt")
++            message(FATAL_ERROR "FAILED TO CHECKOUT RTOSC\n"
++            "please check file permissions and your network")
++        endif()
++    else()
++        message(STATUS "Found Rtosc Submodule...")
+     endif()
+-else()
+-    message(STATUS "Found Rtosc Submodule...")
+-endif()
+ 
+-set(RTOSC_NO_INSTALL TRUE)
+-include("rtosc/cmake/ColorMessage.cmake")
+-add_subdirectory(rtosc)
+-include_directories(rtosc/include)
++    set(RTOSC_NO_INSTALL TRUE)
++    include("rtosc/cmake/ColorMessage.cmake")
++    add_subdirectory(rtosc)
++    include_directories(rtosc/include)
++endif()
+ 
+ enable_testing()
+ include(CTestConfig.cmake)
+--- a/src/CMakeLists.txt	2022-01-22 02:46:21.000000000 +0100
++++ b/src/CMakeLists.txt	2023-05-03 23:17:58.411667901 +0200
+@@ -575,13 +575,27 @@
+     set(PTHREAD_LIBRARY pthread)
+ endif()
+ 
+-target_link_libraries(zynaddsubfx_core
+-	${ZLIB_LIBRARIES}
+-	${FFTW3F_LIBRARIES}
+-	${MXML_LIBRARIES}
+-	${OS_LIBRARIES}
+-    ${PTHREAD_LIBRARY}
+-    rtosc rtosc-cpp)
++if(ZYN_SYSTEM_RTOSC)
++    target_link_libraries(zynaddsubfx_core
++        ${ZLIB_LIBRARIES}
++        ${FFTW3F_LIBRARIES}
++        ${MXML_LIBRARIES}
++        ${OS_LIBRARIES}
++        ${PTHREAD_LIBRARY}
++        ${RTOSC_LIBRARIES}
++        ${RTOSC_CPP_LIBRARIES}
++    )
++else()
++    target_link_libraries(zynaddsubfx_core
++        ${ZLIB_LIBRARIES}
++        ${FFTW3F_LIBRARIES}
++        ${MXML_LIBRARIES}
++        ${OS_LIBRARIES}
++        ${PTHREAD_LIBRARY}
++        rtosc
++        rtosc-cpp
++    )
++endif()
+ 
+ if(IwyuErr)
+     message (STATUS "Include what you use: ${IwyuErr}")
+
+
+When ZYN_SYSTEM_RTOSC is ON, port-checker file is not available and the test
+fails.
+
+--- a/src/Tests/CMakeLists.txt	2022-01-22 02:46:21.000000000 +0100
++++ b/src/Tests/CMakeLists.txt	2023-05-04 00:19:01.635383149 +0200
+@@ -65,7 +65,6 @@
+ 
+     if(LIBLO_FOUND)
+         cp_script(check-ports.rb)
+-        add_test(PortChecker check-ports.rb)
+     endif()
+     add_executable(save-osc SaveOSC.cpp)
+     target_link_libraries(save-osc
