yosemite won't open audacity 2.1.1

I have download Audacity 2.1.1 (from ausacityteam.org) to my Mac Yosemite OK but when I tried to open it I got the message:

“Audacity” can’t be opened because it is from an unidentified developer.

Is there any way I can get round this? Or is it better if I download an older version of Audacity? If so, which old version should that been?

Most appreciated if someone can help. I am not techno-literate, so may need a bit more detailed info,help and explanation.

Thanks.

audaInYose

See here in the FAQ: http://manual.audacityteam.org/o/man/faq_installation_and_plug_ins.html#mac_launch