Guitar Heroes OTB, Vol. 4 is a 5-track EP released by David Garfield on March 24, 2023, via his Creatchy Records label. "OTB" stands for "Outside the Box," a series of releases where Garfield collaborates with legendary musicians across various genres. 

This specific volume features a high-profile lineup of guitarists and session players, including several recurring collaborators from your previous questions like Vinnie Colaiuta and Michael Landau.

The EP includes the following tracks and featured artists:

1. Dirty Grease (Extended Version): Featuring Joe Bonamassa, Robben Ford, and Doug Bossi. Drummer: Vinnie Colaiuta


2. Sea of Truth: Featuring Will Lee, Benmont Tench (The Heartbreakers), Tim Pierce, and James Harrah. Drummer: Gregg Bissonette (This track is a vocal-heavy session where Bissonette typically handles the Outside the Box series rhythm duties alongside bassist Will Lee)


3. Tsunami (Remastered 2023): A Steve Tavaglione track featuring Allan Holdsworth, Michael Landau, and Vinnie Colaiuta.


4. All Blues (Remastered 2023): Credited to Karizma, featuring Steve Lukather, Michael Landau, and Nathan East.
   Drummers: Jeff Porcaro & Vinnie Colaiuta (This legendary "Double Drummer" session was originally recorded by Los Lobotomys at The Complex in 1989 and remastered for this release)


5. Voodoo Gumbo / Citizen Coryell: Featuring Larry Coryell and Airto Moreira.

The "All Blues" track is particularly significant as it features both Jeff Porcaro and Vinnie Colaiuta playing together. This specific 1989 session is a hallmark of the L.A. session scene and David Garfield's various projects.

The series is known for unearthing rare recordings; for instance, Vol. 1 of this series famously features a previously unreleased cover of "If 6 Was 9" with Eddie Van Halen.