diff --git a/music21/instrument.py b/music21/instrument.py
index 16becc2d6..11f0cb59b 100644
--- a/music21/instrument.py
+++ b/music21/instrument.py
@@ -9,7 +9,7 @@
 #               Ben Houge
 #               Mark Gotham
 #
-# Copyright:    Copyright © 2009-2024 Michael Scott Asato Cuthbert
+# Copyright:    Copyright © 2009-2026 Michael Scott Asato Cuthbert
 # License:      BSD, see license.txt
 # ------------------------------------------------------------------------------
 '''
@@ -2544,10 +2544,15 @@ def getAllNamesForInstrument(instrumentClass: Instrument,
     Note that the language string is not case-sensitive, so 'German' is also fine.
     '''
 
+    from music21.languageExcerpts import instrumentLookup
+
     language = language.lower()
     instrumentNameDict = {}
 
-    instrumentClassName = instrumentClass.instrumentName or ''
+    namedClasses = set(instrumentLookup.allToClassName.values())
+    instrumentClassName = next((cls.__name__ for cls in type(instrumentClass).__mro__
+                                if cls.__name__ in namedClasses),
+                               instrumentClass.instrumentName or '')
 
     if language == SearchLanguage.ALL:
         for lang in SearchLanguage:
@@ -2569,6 +2574,18 @@ class TestExternal(unittest.TestCase):
 
 class Test(unittest.TestCase):
 
+    def testGetAllNamesForInstrumentByClass(self):
+        acousticBass = getAllNamesForInstrument(AcousticBass(), SearchLanguage.ENGLISH)
+        self.assertEqual(acousticBass, {'english': ['acoustic bass']})
+
+        firstViolins = Violin()
+        firstViolins.instrumentName = 'Violin I'
+        self.assertEqual(getAllNamesForInstrument(firstViolins, SearchLanguage.ENGLISH),
+                         {'english': ['violin', 'violins']})
+
+        self.assertEqual(getAllNamesForInstrument(Instrument('Violin'), SearchLanguage.ENGLISH),
+                         {'english': ['violin', 'violins']})
+
     def testCopyAndDeepcopy(self):
         from music21.test.commonTest import testCopyAll
         testCopyAll(self, globals())