The seriousness of his opening statement 'set the tone' for/of the meeting. [=his opening statement established that the meeting would be serious]
('Brit') I keep getting the 'engaged tone'. [=('US') 'busy signal'; the sound which indicates that the telephone line is already being used]
People will be more likely to listen to you if you 'tone down' your language a little.
(..) I'm taking shifts for Sjöfn at the moment. Don't you deserve better than to chase after a depressed garbage lady? - Mom! - What was that tone? What? - Don't you talk to me in that tone. - What tone? The tone you used just now. I wasn't using a tone. Yes you were. And it was a nasty tone. You're becoming a real chef. I guess she doesn't cook much. Is she good at anything? You're not getting serious with her, are you? (..)2015 Virgin Mountain