Yes. The maj7th is just that, as opposed to the dominant or flat 7th we use in blues a lot. So in C, the flat 7 is Bb. If we play C E G Bb we have just played a C7 chord.
If we raise the 7 it becomes a B natural and therefor a major 7. So C E G B is a major t chord which sounds totally different from the dominant 7 chord.