Bard Instrument Modifier Question

[Alarria]

Hi all,

Just trying to calculate how instrument modifiers work for bard songs. I feel as though I remember that an instrument with a mod of say 23 (Walrus Skin Drum) add 230% to the power of the song? Like if I used Tuyen's Chant of Frost at level 60, which according to the wiki does 31 damage per tick would it increase to ~71 per tick? Similarly, would hymn of restoration go from 13 healing per tick to 29 per tick using a 22 instrument (Lute of the Howler)- rounded up from 28.6.

Trying to find how much a full round of dots would do. I also can't remember for dots to get full damage if they must be fleeing, or snared, or rooted or whatever.

Thanks for the help!