Vibraphone Solo - Digital Download SKU: A0.1032339 Composed by Mark Clifford. 20th Century,Contemporary,Instructional. Individual part. 4 pages. Mark M Clifford #4756721. Published by Mark M Clifford (A0.1032339). I'm Sorry About What I Said, I Probably Just Needed A Sandwich is a vibraphone etude by Bay Area composer and improvisor Mark Clifford. This etude is for the intermediate/advanced vibraphonist. It explores constant interval structure, mallet rotation, and octave accuracy. Additionally, I'm Sorry... employs the use of open notation that leaves room for the performer to improvise with the given material.