tondee I was saying that when you usually think of a major 11th chord the 11th is usually #11 but for clarity you have to put the sharp in or the player will think you want a natural 11th note. Now in minor 11th chords the 11th is natural. Now any chord can use different chord tones # or b but I'm talking about the prefered. Now if you use the #11 note it may or not be apart of the scale that you're using. It would be dependent on first what particular scale you are using and second what degree of chord you are using.
For example in a traditional major scale if I make the I /tonic/root chord to base a 11th chord if I use the #11 then that 11th note would not be apart of that scale it would be what theorists call a borrowed tone since it is not apart of that major scale. However if I build a 11th chord based on the IV degree or subdominant chord then I would not have to sharpen the 11th with a borrowed tone since the #11 of the IV chord is already apart of that scale. But for the lead sheet chord designation above the musical staff I would have to indicate that it's a #11. So if I was in Cmajor than for !V chord I would write Fmaj 9, #11.
I hoped that helped clarity it for you.
