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.
(..) And vingt-quatre Haxo, it's not an ID stamp. It's a street address. This is Jacques Sauni're. Please leave a message after the tone. Please, Monsieur Sauni're, pick up the phone. This is Sandrine Bieil. I have called the list. I fear the other guardians are dead. (..)2006 The Da Vinci Code