"First Call"
?
LE
now I am confused, I mean the notes are not all the same, but some of them match....
you might be close LE with "The first call" although I am not 100% convinced , 
but its the best so far..........or my brain isn't able to handle it , give me a moment to clear it, I need a third party 
thanks 
Hey LE, I think you are very close... I was on a similar wavelength (pun intended)... I was thinking at first that this was a trumpet from the Big Band era. And while I still can't place it, I am also wondering if this could be a Chuck-Berry-kind of riff.
So I sent the clip from IUTC over to a good friend, and he immediately pulled "First Call" (used in horse races), and said it sounded like MK "quoted" it (BTW, it's kind of fun putting quotation marks around the word "quoted" hehehe).
Also, my friend DID agree that the riff sounded Chuck Berry-esque.
Lis,
I have compared the "First Call" and the Use to Could solo "tune" simultaneous couple times,
and you may think that Mark improvised a bit, but that is the point for me, what Mark plays I know note by note,
I can play it note by note (no big deal) on my guitar.
A local band in North-Holland (Beverwijk) known as the Ruud Jansen Band, named after the band leader's name Ruud Jansen (GREAT keyboard virtuous BTW) used that exact tune , the way Mark plays it, before they took a break, but that was years ago, and the band changed members often since then, I don't know any of them in person, but I will see if they play the neighborhood soon, to ask it Ruud Jansen.........and hope he remembers that "we take a break-tune"
And I just stopped watching numerous of Chuck Berry clips on you-tube , hoping I was lucky to find that riff in a song of his,
because it is played indeed in a CB kind of way.
Was great to hear all his great songs and blues licks, so it was not a punishment
