Ms Mackey was treated for trauma and shock during the horror ordeal during the early hours of yesterday morning.
Ms Mackey is the girlfriend of the victim's brother, Dylan Creane (28), who was stabbed eight times and suffered a punctured lung.
Boss Volenti have become well known to Dublin's music scene with regular gigs at the capital's music haven, Whelan's on Wexford Street, and previously performed at the summer festival Electric Picnic.
They have even opened for acclaimed New York indie band We Are Scientists as well as Irish grown success stories, Republic of Loose and The Frames.
Following the release of their debut album in 2006, the band were nominated for a prestigious Meteor award for Best New Irish Act in 2007, and have been enjoying escalating success since.
Although the band lost to another rock band, Director, they were accompanied by The Blizzards, who have achieved phenomenal success since as well as band, Duke Special.
RTE Guide raved: "This debut from Dubliners' Boss Volenti is so damn authentic that it should have the words 'classic rock' scratched into its very grooves."
Boss Volenti has been compared to Kings of Leon and Queens of the Stone Age and praised by critics for their unique sound.
Ms Mackey, the only person in the house left physically uninjured will be healing the emotional wounds she suffered after witnessing the horrific attack as well as tending to her boyfriend.
Seb Creane and his killer, Shane Clancy, were both 22-year-old students.
After killing his friend and stabbing two others, Mr Clancy turned the knife on himself.
Seb was best known for his passion for photography and was pursuing his graphic design studies at Dun Laoghaire Institute of Art and Design.