There are two aspects to tension. What a harpist calls tension is often how hard you can/need to pull on the strings – so a very responsive harp will be perceived as lower tension even thought the pull on the strings between tuning peg and soundboard, which a physicist calls tension, is the same.

For a given pitch the physical tension will depend on the length and mass of the string. If you have two harps of different sizes but the same strings the one with longer strings will need the higher tension to pull each string to pitch.

Also, a more massive string will need more tension to bring it to a given pitch. Mass (or more precisely mass for a given length) of string can be altered in two main ways. Firstly by changing the thickness of the string. Concert gut is thicker than lever gut so higher tension. Similarly concert fluorocarbon is thicker than lever fluorocarbon and higer tension. Different materials also have different densities so changing a string from nylon to one *of the same thickness* in the more dense fluorocarbon will increase the tension. However, harpists usually don’t buy strings by thickness and if you buy a middle C string in nylon and one in fluorocarbon the nylon one will be thicker. Any harpbuilder who wanted to could make high, low or medium tension harps strung in any of the three materials mentioned.

For comparison, I’ve played the Prelude, Troubador and a Stoney End lever harp. The L&H harps had a higher tension in my opinion. They sounded really good but definitely required more work, so to speak. I didn’t want a big whopping harp to cart around, however, so I opted for the Stoney End Briar Rose. I would say the tension is medium. It also sounds really good, and is easier to pull the strings than the L&H harps, but it isn’t floppy or light in tension at all. They also have a fantastic rent to own program at Stoney End and I highly recommend their harps! The Briar Rose is a smaller floor harp, but it’s easier to transport than a bigger harp. It’s still a bit awkward though, just because of the shape/size.

I currently have a loaner lap harp that has really light tension. I don’t know who made it.. someone in Tennessee. It has a very consistent tone and sounds fine, but the tension seems very loose and I tend to overplay it. I don’t care for it and prefer a closer to medium tension feel.

Patricia, you can get cheap micrometers which are useful for strings and all sorts of other things from most budget tool sources (eg ebay). Plain wire gauges are available too, but usually marked up with gauge numbers so easier to use for comparison than recording a measurement in mm or 001″.