tensionless

Mr. Diaz instead played the opening movement with a cool, gentle, tensionless tone.

But these came peeking through stretches of diffuse and tensionless playing like rays of sunlight on a dreary day.

For example, his work on the death instincts in Beyond the Pleasure Principle is based on the assumption that he needs to show that all organisms, including mankind, aim to return to a tensionless state of inorganic matter.