Possible Clues:

• Very significant
• Second American keeps ring for major
• Important opus oddly written within minutes
• The instant it gets around us it gets to be most important
• How medical men get over to us in a very big way
• It's most important to get the medicine men to us
• ...and after that there's nothing America finds crucial
• There's little time round us for anything so significant (9)
• It's most important to get just a little time round us
• Even so short time round us may be very important