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diff --git a/src/test/java/com/jsyn/research/BenchMultiThreading.java b/src/test/java/com/jsyn/research/BenchMultiThreading.java
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+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.research;
+
+import org.junit.jupiter.api.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+// TODO: Use thread pools, or maybe JMH?
+public class BenchMultiThreading {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(BenchMultiThreading.class);
+
+    private static final int FRAMES_PER_BLOCK = 64;
+    int numThreads = 4;
+    int numLoops = 100000;
+    private ArrayList<CustomThread> threadList;
+
+    static class CustomThread extends Thread {
+        long frameCount = 0;
+        long desiredFrame = 0;
+        Object semaphore = new Object();
+        Object goSemaphore = new Object();
+        volatile boolean go = true;
+        long startNano;
+        long stopNano;
+        long maxElapsed;
+
+        @Override
+        public void run() {
+            try {
+                startNano = System.nanoTime();
+                while (go) {
+                    // Watch for long delays.
+                    stopNano = System.nanoTime();
+                    long elapsed = stopNano - startNano;
+                    startNano = System.nanoTime();
+                    if (elapsed > maxElapsed) {
+                        maxElapsed = elapsed;
+                    }
+
+                    synchronized (semaphore) {
+                        // Audio synthesis would occur here.
+                        frameCount += 1;
+                        // LOGGER.debug( this + " generating frame  " +
+                        // frameCount );
+                        semaphore.notify();
+                    }
+                    synchronized (goSemaphore) {
+                        while (desiredFrame <= frameCount) {
+                            goSemaphore.wait();
+                        }
+                    }
+                    long stopNano = System.nanoTime();
+                }
+            } catch (InterruptedException e) {
+                LOGGER.debug("CustomThread interrupted. ");
+            }
+            LOGGER.debug("Finishing " + this);
+        }
+
+        public void abort() {
+            go = false;
+            interrupt();
+        }
+
+        public void waitForFrame(long targetFrame) throws InterruptedException {
+            synchronized (semaphore) {
+                while (frameCount < targetFrame) {
+                    semaphore.wait();
+                }
+            }
+        }
+
+        public void generateFrame(long desiredFrame) {
+            synchronized (goSemaphore) {
+                this.desiredFrame = desiredFrame;
+                goSemaphore.notify();
+            }
+        }
+
+    }
+
+    @Test
+    public void testMultiThreads() {
+        threadList = new ArrayList<>();
+        for (int i = 0; i < numThreads; i++) {
+            CustomThread thread = new CustomThread();
+            threadList.add(thread);
+            thread.start();
+        }
+
+        long frameCount = 0;
+        long startTime = System.currentTimeMillis();
+        try {
+            for (int i = 0; i < numLoops; i++) {
+                frameCount += 1;
+                waitForThreads(frameCount);
+                // LOGGER.debug("got frame " + frameCount );
+            }
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        long stopTime = System.currentTimeMillis();
+        long elapsedTime = stopTime - startTime;
+        double elapsedSeconds = 0.001 * elapsedTime;
+        double blocksPerSecond = numLoops / elapsedSeconds;
+        System.out.format("blocksPerSecond = %10.3f\n", blocksPerSecond);
+        double framesPerSecond = blocksPerSecond * FRAMES_PER_BLOCK;
+        System.out.format("audio framesPerSecond = %10.3f at %d frames per block\n",
+                framesPerSecond, FRAMES_PER_BLOCK);
+
+        for (CustomThread thread : threadList) {
+            System.out.format("max elapsed time is %d nanos or %f msec\n", thread.maxElapsed,
+                    (thread.maxElapsed / 1000000.0));
+        }
+        for (CustomThread thread : threadList) {
+            assertEquals(frameCount, thread.frameCount, "BlockCount must match ");
+            thread.abort();
+        }
+
+    }
+
+    private void waitForThreads(long frameCount) throws InterruptedException {
+        for (CustomThread thread : threadList) {
+            // Ask threads to wake up and generate up to this frame.
+            thread.generateFrame(frameCount);
+        }
+        for (CustomThread thread : threadList) {
+            // Wait for all the threads to catch up.
+            thread.waitForFrame(frameCount);
+        }
+    }
+}