Islamist hymns posted on YouTube have become a powerful propaganda tool used by jihadists to win hearts and minds and to recruit followers, according to a terrorism expert.

Moutaz Alkheder, of the University of St Andrews, found that the Syrian revolution marked a turning point as for the first time jihadists Islamised traditional songs to mobilise people on a large scale.

He examined a sample of the 20 most-viewed Islamist extremists' hymns (nasheeds) on YouTube and found that most jihadi nasheeds call for the use of a maximum level of violence and brutality, in a passionate way that might be termed the "romanticisation of brutality".

He said: "Cognisant of the success of the secular songs and outdoor celebrations of the peaceful Syrian protesters, jihadists adopted the style while replacing with nasheeds so as to widen the jihadists' appeal and attract the sympathies and loyalties of Syrian protesters.

"The importance of the Syrian conflict in particular is that this Islamised style of protest has become a model to be imitated by other jihadists."

His research found that these nasheeds resonate on the battlefield, helping to radicalise people and recruit new terrorists, or at least help gain sympathisers outside their immediate territory through the internet.

They also endow the jihadist cause with an emotional dimension.

He also suggests this new tendency demonstrates a high level of pragmatism among these terrorist groups since they do not hesitate to resort to tools which have long been viewed by them and their theologians as heresy, morally corrupt and forbidden (haram).

The nasheeds also display nostalgia for an Islamic golden age and, in contrast to the older nasheeds which focused on the perceived victimisation of Muslims, post-Arab Spring nasheeds tend to depict jihadists as having the upper hand, assertive and positive.

Researchers say that analysing the content of these songs can help them deconstruct the terrorist message and understand the terrorist mentality.

The postgraduate student in the university's terrorism studies programme will present his analysis of the propaganda power of Islamised hymns at the university's third biennial conference on Syria between July 1 and 3.

The international conference will bring together a wide range of scholars of Syria.

Participants include Professor David Lesch, Steven Heydemann of the United States Institute of Peace, Lord Williams and William Zartman, an expert on conflict resolution in failed states.