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diff --git a/src/com/jsyn/unitgen/VariableRateStereoReader.java b/src/com/jsyn/unitgen/VariableRateStereoReader.java
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+++ b/src/com/jsyn/unitgen/VariableRateStereoReader.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.unitgen;
+
+import com.jsyn.ports.UnitOutputPort;
+
+/**
+ * This reader can play any SequentialData and will interpolate between adjacent values. It can play
+ * both envelopes and samples.
+ * 
+ * @author Phil Burk (C) 2009 Mobileer Inc
+ */
+public class VariableRateStereoReader extends VariableRateDataReader {
+    private double phase;
+    private double baseIncrement;
+    private double source0;
+    private double current0;
+    private double target0;
+    private double source1;
+    private double current1;
+    private double target1;
+    private boolean starved;
+    private boolean ranout;
+
+    public VariableRateStereoReader() {
+        dataQueue.setNumChannels(2);
+        addPort(output = new UnitOutputPort(2, "Output"));
+        starved = true;
+        baseIncrement = 1.0;
+    }
+
+    @Override
+    public void generate(int start, int limit) {
+        double[] amplitudes = amplitude.getValues();
+        double[] rates = rate.getValues();
+        double[] output0s = output.getValues(0);
+        double[] output1s = output.getValues(1);
+
+        for (int i = start; i < limit; i++) {
+            // Decrement phase and advance through queued data until phase back
+            // in range.
+            if (phase >= 1.0) {
+                while (phase >= 1.0) {
+                    source0 = target0;
+                    source1 = target1;
+                    phase -= 1.0;
+                    baseIncrement = advanceToNextFrame();
+                }
+            } else if ((i == 0) && (starved || !dataQueue.isTargetValid())) {
+                // A starved condition can only be cured at the beginning of a block.
+                source0 = target0 = current0;
+                source1 = target1 = current1;
+                phase = 0.0;
+                baseIncrement = advanceToNextFrame();
+            }
+
+            // Interpolate along line segment.
+            current0 = ((target0 - source0) * phase) + source0;
+            output0s[i] = current0 * amplitudes[i];
+            current1 = ((target1 - source1) * phase) + source1;
+            output1s[i] = current1 * amplitudes[i];
+
+            double phaseIncrement = baseIncrement * rates[i];
+            phase += limitPhaseIncrement(phaseIncrement);
+        }
+
+        if (ranout) {
+            ranout = false;
+            if (dataQueue.testAndClearAutoStop()) {
+                autoStop();
+            }
+        }
+    }
+
+    public double limitPhaseIncrement(double phaseIncrement) {
+        return phaseIncrement;
+    }
+
+    private double advanceToNextFrame() {
+        dataQueue.firePendingCallbacks();
+        if (dataQueue.hasMore()) {
+            starved = false;
+
+            dataQueue.beginFrame(getFramePeriod());
+            target0 = dataQueue.readCurrentChannelDouble(0);
+            target1 = dataQueue.readCurrentChannelDouble(1);
+            dataQueue.endFrame();
+
+            // calculate phase increment;
+            return synthesisEngine.getFramePeriod() * dataQueue.getNormalizedRate();
+        } else {
+            starved = true;
+            ranout = true;
+            phase = 0.0;
+            return 0.0;
+        }
+    }
+
+}