Why my dog barks frequently when people come over in my apt. to hang out. He also has this separation anxiety

My dog starts barking when everyone is having fun. He sometimes keep calm and then suddenly just bark in front of people. I live in a good size studio apartment. He is a good dog. Never did harm to people. What should I do? He just turned 8 yrs. old. By the way, sometimes in the elevator he keeps quiet and other times, he will just bark with strangers. But this does not happen all the time. I forgot to mention that his breed is mix german/lab. Hope I can find some suggestions or help today. Thanks.

If you have the time take him to obedience..they work wonders. Good Luck.

Dog Separation Anxiety