diff --git a/content/zettels/tuned_mass_damper.md b/content/zettels/tuned_mass_damper.md
index 0c419aa..7f1721a 100644
--- a/content/zettels/tuned_mass_damper.md
+++ b/content/zettels/tuned_mass_damper.md
@@ -16,8 +16,12 @@ The basic idea is to damp the resonance of a structure (called the primary syste
 Usually, the resonance frequency of the TMD should match the resonance of the primary system that is to be damped.
 The TMD then has large internal damping such that the energy is dissipated (i.e. the resonance of the primary system is well damped).
 
+Below is a lecture about tuned mass damper.
+
 {{< youtube qDzGCgLu59A >}}
 
+And a simple experiment showing how a tuned mass damper works with a vibration cantilever beam.
+
 {{< youtube HDa1VO1VDpc >}}