diff --git a/Source/PluginEditor.cpp b/Source/PluginEditor.cpp
index d62c57f..6b56093 100644
--- a/Source/PluginEditor.cpp
+++ b/Source/PluginEditor.cpp
@@ -433,7 +433,7 @@ void TrommelkisteEditor::timerCallback()
     const double now = juce::Time::getMillisecondCounterHiRes() / 1000.0;
     for (int i = 0; i < NUM_TRACKS; ++i)
     {
-        if (proc.trackActive[i])
+        if (proc.trackActive[i].exchange(false))
             trackActivatedTime[i] = now;
     }
     repaint();
diff --git a/Source/PluginProcessor.cpp b/Source/PluginProcessor.cpp
index e681902..2347c98 100644
--- a/Source/PluginProcessor.cpp
+++ b/Source/PluginProcessor.cpp
@@ -57,9 +57,6 @@ void TrommelkisteProcessor::processBlock(juce::AudioBuffer<float>& buffer, juce:
     const int numSamples = buffer.getNumSamples();
     buffer.clear();
 
-    for (int i = 0; i < NUM_TRACKS; ++i)
-        trackActive[i] = false;
-
     // Shuffle: add ghost notes (bar-quantized)
     const float globalShuffleAmt = apvts.getRawParameterValue("global_shuffleAmount")->load();
     const float globalGroove = apvts.getRawParameterValue("global_groove")->load();
diff --git a/Source/PluginProcessor.h b/Source/PluginProcessor.h
index 1cfaba5..6abc340 100644
--- a/Source/PluginProcessor.h
+++ b/Source/PluginProcessor.h
@@ -2,6 +2,7 @@
 #include <juce_audio_processors/juce_audio_processors.h>
 #include <juce_audio_formats/juce_audio_formats.h>
 #include <juce_dsp/juce_dsp.h>
+#include <atomic>
 #include <random>
 
 static constexpr int NUM_TRACKS = 10;
@@ -50,7 +51,7 @@ public:
     };
 
     Track tracks[NUM_TRACKS];
-    bool trackActive[NUM_TRACKS] = {};
+    std::atomic<bool> trackActive[NUM_TRACKS] = {};
     juce::AudioProcessorValueTreeState apvts;
 
     // Sample library