This likely refers to the Children's Music Network or similar initiatives that use music to encourage cooperation and social justice.
The phrase appears to be a specific identifier or social media handle related to a niche creative project or a personal digital archive, likely combining "tanc" (dance/movement in several Slavic languages), "nežnosť" (tenderness), and "musicforchildren." Contextual Meaning tanc_neznost_at_musicforchildren
The inclusion of "tanc" (dance) suggests a pedagogical or artistic focus on movement for younger audiences. This likely refers to the Children's Music Network