Vinjar studied ethno-musicology at the University of Oslo.
His work spans the whole range between abstract approaches, theory, algorithmic composition, developing special-purpose programming languages - to collecting and using field-recordings from nature and culture.
Vinjars list of works contains electroacoustic music, music for instruments, vocal, interactive web-art, music for stage and installations. He collaborates with ensembles and venues such as SISU, Poing, Cikada, EAU, Ultima, ZKM, CCRMA and many others.
He collaborates with developers at main institutions for music-technology IRCAM, ZKM, CCRMA to develop Open Source software for composition (CAC), especially those based on Lisp (Common Lisp, Scheme), such as Open Music, LilyPond and CLM/Snd. At times Vinjar does workshops and lectures in CAC, partly as Professor II at the Norwegian Academy of Music.
Vinjar also works actively with performing music. He played a key role in establishing EAU - Electric Audio Unit - a performers group which specialized in electroacoustic music and 3D audio. EAU was a very active performer in Norway and abroad, and since its beginning and up to 2021, EAU commissioned more than 45 new works, premiered 100, and played more than 400 concerts.