Criticism, when constructive, is one of the only truly effective catalysts for change. How can you make right what you don't know is wrong?
From a musicians perspective, have you ever had someone ask you to switch it up? In the middle of rehearsal, your bandleader stops the song and says, "Hey, I'm just not feeling that guitar part. Can we try something else?"
It says a lot about a guitarist when he or she is confident enough to take that criticism without beginning to doubt their ability to play. Just switch it up. Maybe the song is less you now, but you'll get points from everyone in the band for how you roll with the changes and fit the vision of your bandleader.
Same goes for any career, really. Be teachable. Be flexible. Be willing to try some other approach. Who knows, after trying their idea they may find they liked yours better.
Negativity is a whole other beast. Criticism and negativity are actually opposites. I'm willing to bet you know a negative person—that person for whom the glass is not just half empty, it actually contains a deadly choking hazard.
You know, the people who are so constantly doom and gloom, as if the sky could fall at any moment?
It may be the bandleader who can't ask the band to switch it up without throwing his hands up saying, "This sucks—I hate this arrangement." It may be the band that lets technical difficulties ruin their entire set. They've forgotten how to entertain a crowd without all the gear and lights.
That kind of negative thinking and negative influence will destroy your career. Put those people out of your life! Strive hard not to be a negative person. Think positively, speak positively, act positively. When giving criticism, feedback, or suggestions, do so constructively.
Encouragement goes a long way with people, but when you consider the end result, specific and actionable feedback can often be more positive than a pat on the back. People will know that you truly value them by your honesty and commitment to seeing them succeed.
The most attractive people in the world are those who smile. Those who turn poor circumstances into a wonderful outcome by remaining positive. Those who persistently shift tired paradigms, choosing to empower others around them.