Conversation so far:
when did Berry die?
March 26, 2004.
what did he die of?
after he suffered a seizure eight days before his 63rd birthday.
where was he buried?
his body was cremated.
why was he cremated?
CANNOTANSWER.
Did they have a wake or viewing for him?
a "Celebration of Life" was held in Berry's memory at the Roxy Theatre on the Sunset Strip in West Hollywood, California.
who attended the celebration of life?
Attendees included Torrence, Lou Adler, Jill Gibson, and Nancy Sinatra, along with many family members, friends, and musicians.
how did Dean react after the death?
Dean's website, features--among other things--rare images, a complete Jan & Dean discography.

Question: did he release any songs that Jan had written or sung before death?
Self-contained rewrite: did Dean release any songs that Jan Berry had written or sung before death?