My iMac will not read cd

I have tried insert a music cd in my iMac (late 2010/27/Yosemite). The iMac does not seem to recognize the disc but keeps on trying to make it run. Over and over again you can hear the sound of the drive attempting to start the cd running but all in vain.

I cannot eject the cd - neither by pressing the eject button or by shutting down the computer or following other pieces of advice. As the cd is not shown on the desktop I cannot pull it to the thrash either.

Any other suggestions?