Uli Jon Roth

In this photo, Roth can be seen playing his signature Sky Guitar, complete with a 30+ fret scalloped fretboard, this guitar appears to be scalloped from the 6th fret onward, with the first five frets appearing to be unscalloped for heavier chording & riffing.

Wikipedia also notes Roth's use of scalloped necks in his signature model guitars:

"Sky guitars" "Roth commissioned construction of custom guitars with additional frets from luthier Andreas Demetriou In the 1980s. Roth has had five of these "Sky" guitars made. To be able to emulate the high notes of a violin, all of the Sky Guitars have more frets than a typical electric guitar. The first Sky Guitar (used on the album Beyond the Astral Skies) had 30 frets. Later versions of the Sky Guitar overcame the problem of the higher register frets becoming too narrow by widening the frets by whole steps for the highest notes. In an April 2001 Guitar Player magazine interview Roth reported that the guitars are either fretless above the 30th fret, or have whole step fret spacing above the 27th fret, with 35 effective (half step) frets. All of the Sky Guitars with frets have scalloped fretboards. The Sky Guitar's pickups are custom 4-coil humbuckers, made by John Oram, with one guitar having an Oram pickup hidden under the 24th fret. For a time, Roth used a Framus Dragon amplifier, although currently he promotes Blackstar Artisan 100 & Series One 200 Watt heads. He has also used a stalk mounted Vibesware guitar resonator (sustainer) to introduce infinite sustain as on the instrumental Benediction on his Under A Dark Sky album. Dean Guitars produced 25 Custom Sky Guitars based on Roth's custom models with six and seven strings in 2011."

Roth has been playing scalloped fretboards since is days in Scorpions as stated in this segment from an April 2001 Guitar Player Magazine interview:

"There are five Sky guitars in existence, — three 6-strings and two 7-strings," Uli Jon Roth says. "The 7-strings have a low B and a range of over five-and-a-half octaves. When you have more than 30 frets, it gets very awkward to play in the upper register because the frets are so close together. So one of my guitars is actually fretless at the top. On another, I space the frets out in whole-tone increments. I can still get the half-steps, but I have to jump over to another string to get them. The fretboards are scalloped — which is something I never did to my Strats back in the Scorpions. It's still a hindrance for playing rhythm, but I definitely prefer a scalloped neck for single-note work — it gives me much more control over the notes."

Roth's signature Sky Guitars come fitted with John Oram 4-Coil Custom Humbuckers as explained by their official website:

"The MEGA-WING III SYSTEM is the heart of the sound engine of all Master built Sky Guitars."

"This revolutionary active pickup system is unlike any other and will put an unprecedented amount of tonal control at your disposal."

"This is coupled with an incredible amount of output. By means of the ingenious addition of a master gain control it enables you to make any amplifier sing without extra gadgets."

"The MEGA-WING III SYSTEM was developed by award-winning inventor and analogue sound designer genius John Oram (“aka Father-of-British-EQ”) in close co-operation with Uli Jon Roth. The low-impedance pick-ups are hand-wired by Boris & Fiona Dommenget and are fine-tuned to perfection to interface with the EQ and gain stages of the sound engine."

"The MEGA-WING concept is unique in the world of the electric guitar and the result is the most powerful and most versatile guitar pick-up system ever built."