Bap only found out when he was dying last year just how big an impact his songs have had all over the world. He was inundated with messages of support after starting a moving blog about his illness on his website. Even after his death on November 1 last year the messages from fans continued in their thousands and, Brenda says, are still coming in to this day.
Hard as the last year has been for her and her two children, Christine and Kenneth, Brenda says all three of them have been devoted to keeping Bap's music alive through his website.
Among the many songs recorded by Bap, some of the most personal - and often mentioned by fans - were The Right Stuff, Under My Wing, Howl On, The Beauty of You, Moonlight Kiss and Working Man. He had a prolific output from his days with Energy Orchard at the end of the Eighties and throughout his solo career, which included collaborations with music greats Van Morrison, Steve Earle, Mark Knopfler and Shane MacGowan, and released his last album shortly before his death.
As the anniversary of his death approaches on November 1, Brenda decided to mark it by releasing a song from his last album Reckless Heart on his website each day. She says: "He has left me a role in terms of his music. It meant everything to him, which is clear from his blog. If anyone ever wants to understand Bap, they just have to read his blog. Music is what made him tick and when he started his blog, he got so many emails and messages, which made him realise just how many people his music had touched from all corners of the world.
"It broke his heart to find out when it was too late to do anything about it, but at the same time he was very happy to find out, as it was what he always wanted. "He didn't want wealth or fame, he just wanted people to feel the magic of his music and my role now is to continue that and to spread his music, which was so authentic.
"The amount of emails coming in was unbelievable and after he died I got messages from all over the world and I couldn't, even if I had been able to at that time, have physically replied to them all, as there were so many. "There have been thousands and it is still going on."
Bap and Brenda met 10 years ago and from the very start were inseparable. Friends often commented on how happy they made each other. Not only did they share a joint love of music - going on to perform together and touring the world - but both had the high functioning autism disorder, Asperger syndrome.
Brenda is a former solicitor and has written a number of highly acclaimed books on Asperger syndrome. She met Bap when he attended a talk she was giving on it while working with the National Austistic Society.
Bap wasn't diagnosed until his 40s and kept it private, only sharing it on his blog in his final weeks. In a moving piece, he said that his Asperger's had held him back in the music business: "Over the years, I failed miserably to negotiate the music business despite the help of notable musicians such as Steve Earle, Van Morrison and Mark Knopfler; and it ended up taking a huge toll on me."
However, he adds in the blog: "I'm not ashamed of my Asperger syndrome. I've never been ashamed of it. In fact, to be honest I'm proud I've got Asperger's - it is the engine of my creativity."
Brenda and Bap had no idea what lay ahead when on May 7 last year they were packed and ready to drive to a gig in Mayo and Bap suddenly took ill. He was admitted to hospital that day with severe stomach pains and by the following day had received a cancer diagnosis.
He went through major surgery, only to be told his cancer was terminal. He was admitted to Marie Curie Hospice, where he and Brenda shared a room together for the last two months of his life. Brenda was by his side when he passed away on November 1.
She says of their time together: "We had a very intense, wonderfully happy 10 years together. We were joined at the hip.
"We had a blast and we understood each other profoundly. Bap was a very funny guy and anyone who knew him will tell you that. He made me laugh every day.
"We made each other happy, it was completely mutual.
"We spent his last two and a half months together in the Marie Curie Hospice and Bap was really touched and appreciative that I was there, but I said to him that he would have done exactly the same thing as me.
"People he knew used to say they had never seen him as happy as after he met me and my friends used to say the same about me. He was a very private person and when you are in the public eye you have got to get a balance. His Asperger's was a very big deal to him when he got his diagnosis. He always said he wanted to talk about it when the time was right and he said he would know when that would be.
"He prepared his blog and wasn't sure when he was going to use it. When he was in Marie Curie he put it out and he knew it was like sort of saying goodbye.
"He wanted to set the record straight on who he really was, as his Asperger's was such a big part of who he was. I'm so glad he did share it, as I think he is a real role model and there is a lot to be learned from what he went through. His gift, his drive and his dedication - there is a lot for us to learn from all of that.
"Asperger's was how we got together, when Bap came to a talk I was giving on it. I also have Asperger's and we had a massive understanding between each other and were very comfortable together and felt that we could be ourselves with each other. We just became a real unit, a real close team, we clicked in every way."
The past year has been tough and Brenda has found herself withdrawing to cope privately with her grief. She says that her strength comes from Bap and the amazing way in which he accepted his illness.
Her children, Christine and Kenneth, were both very close to Bap and together the three of them have been updating and working on his website to keep his music alive for his many fans, old and new. Brenda says she regards it as a real privilege to be able to spread his music: "The three of us have been working on Bap's website to make it a focal point for all the people who love his music.
"I know he would have loved the idea of what we are doing.
"It is about 18 months since everything fell off the edge of the cliff. It has been a very difficult 18 months and there have been some very dark times.
"Grief is something everybody has been through and there are dark nights of the soul and every journey is different. I needed a lot of time on my own to process things.
"Bap left me so much strength and love and positivity that I know he wouldn't want me to be anything other than positive."
Brenda is not sure yet how she will spend the first anniversary of his death next month, but whatever she plans, it will be private.
In the meantime, she is marking the occasion by delighting fans, new and old, with the daily release of songs from his last album on his website.
It is his music which she believes is now his gift to the world and she wants as many people as possible to listen and enjoy it.
She adds: "Bap was quite a quiet, unassuming, reserved guy off stage and he had so little ego in him.
"Everything he wrote was from the heart and his music evolved over the years and he put so much into his lyrics.
"He always had a very loyal following of people, although he was never mainstream and part of that was to do with his Asperger syndrome.
"When I think of what he went through, even in his darkest hour he was still positive and to me the essence of who he was is a positive person.
"He has left a wonderful gift to the world.
"You just have to listen to his music, it speaks for itself and the world is really in need of it.
"I've been putting the songs from his last album online and the response has been phenomenal, way beyond what I expected, with literally thousands of people listening to track one on the first day alone and getting in touch about how much they love it. Bap would have been delighted.
"I've continued to post the other songs from the album as the month goes on across the social media outlets as well.
"I think every one of us can take great inspiration and encouragement from the way he lived and how he dealt with his illness and everything about him and his values.
"He left such a great gift and I want people to obviously remember his music.
"He was a brilliant, loving, kind man and anyone who knew him will tell you that.
"He was just a fantastic and very special person and he deserves to be honoured and remembered."