I think there's the heart of a good idea here, and it shouldn't be dismissed out of hand. That being said..
On the uses of MusicMusic has existed in every culture, and to each culture it represented many similar things. Culture, home, memory, education, celebration, and sorrow. To this end, music deserve special consideration in this quite unique game. My thoughts on the matter, as inspired by the OP, are the following.
An Aid in WorkingI place this scene before you: A group stands together working on a settlement, conversations pass between members of the group, some bent over the plants of the field, others repairing buildings, and still others grinding seed to produce the flour for baking. Among them all, stands a small group of men with instruments. The festive air of music makes the work easy, and the moods bright, and generally improves all aspects of a days work.
Drum The drum the man holds is of smooth leather, woven cord, well-turned wood, and a bone ring to keep the cords tight, and in turn, the head of the drum. He aspires to own a
doumbek one day, but for now this
bodhran has served him well. Each strike of the drum adds rhythm to the workers efforts as they all time their efforts to the beat of the drum. Work goes more efficiently.
Effects Drummers reduce the time necessary to complete a task for those within a certain radius of the drummer. This radius is increased by a formula involving the Drummers 'Music' Incremental skill, Dexterity, and Psyche, and this same formula determines how much time is shaved off that necessary to complete a task.
Langeleik Next to the drummer sits a man filling the air with the
lovely music of the Lengeleik, adding a lively air to the proceedings, and filling everyone with cheer. With some of the drudgery of their task lightened by these airs, they are inspired and truly learn from the work they perform.
Effects Langeleik players increase the LP learned in the radius they affect. The Langeleik players 'Music' Incremental Skill, Dexterity, and Psyche are used to determine the radius they affect, and how much of an increase to LP those in that area of effect get.
Nyckelharpa Standing with them a man plays a form of fiddle, adding a soothing drone behind the music, as well as a wonderful addition to the already existing music. The sound of this instrument makes every part of the task seem easier, and they find themselves tiring slower.
Effects The Nyckelharpa player decreases the amount of Stamina that is lost by performing at ask, and aids some in it's natural recovery. The Nyckelharpa players 'Music' Incremental Skill, Dexterity, and Psyche are used to determine the radius they affect, and how much the stamina cost is decreased, and how much their natural recovery of Stamina is increased.
Triple-Pipe Amidst this group of players is a man playing a triple-pipe. It's soothing, haunting tunes bring a calming effect on everyone around, even the beasts of the field are affected by this soothing sound. With this sound filling the air, they know they are safe from the beasts of the field.
Effects The Triple-Pipe reduces the likelihood that an otherwise hostile animal will attack those within the radius of it's sound. The Triple-pipe players 'Music' Incremental Skill, Dexterity, and Psyche are used to determine the radius they affect, and how much the likelihood of an attack is decreased.
An Aid in Ritual Each of the above mentioned instruments could also have an affect on Numen earned during sacrifice, using the same stats. This would be of limited utility unless a group gathered to worship, but is a possible use. Further uses in ritual could become apparent should the developers expand upon Worship and Numen.
SynergyFor each additional musician, up to one of each type, the enhancement of each individual musician increases. A band of musicians is better than any one of them alone.
An Aid in Travel Should you be in a vehicle, either a boat or a wagon, and there is a musician along, the vehicle will travel along faster.
An Aid in Combat Musicians playing during combat will affect all those who are set to a color of their choosing within their kin list. Different instruments can increase the effective quality of armor, weapons, and siege equipment within either the radius they affect if on the offensive, or of everyone within a city if defending. In the case of defending those who qualify according to a new permission setting will be affected.
I also think the last posters idea is a grand one, and is to be credited for the addition of the Tripleflute.