Many bass players love that cool, jazzy upright bass tone, but don’t want to drag around a big, bulky upright or deal with having to mic it or mess around with a pickup system.

The Rob Allen short-scale fretless Mouse bass offers solutions to all of those problems.

The Mouse is a lightweight (about 51/2 pounds) instrument that sports a two-piece, single-cut, chambered alder body with a highly figured Claro Walnut top with ivoroid binding. The bolt-on fretless 30″-scale neck is made of maple and capped with a Goncalo Alves fingerboard. The neck has 18 “ghost fret” lines, a flat lacquer finish, and a Corian nut. Builder Rob Allen uses a Martin-style truss rod housed in a square aluminum channel for more even string response and improved attack.

Hardware on the Mouse is minimal; four recessed neck bolts with bushings, and satin-finished Hipshot Ultralite tuners with a satin finish. The Ultralite tuners are a great choice for the light weight Mouse, and help the bass to be very well-balanced.

Electronics are also minimal; a Fishman Matrix natural piezo active pickup, a neatly tucked away volume control on the bridge, and a high-roll-off trim pot in the control cavity. The trim pot is adjusted from the outside of the control cavity cover with a small screwdriver. The 9-volt battery, on the other hand, is inside the cavity, meaning the screws have to be removed to change it. The combination of the walnut top and the lack of any controls gives the mouse a very clean, exotic look.

From a playability standpoint, the Mouse is easy to play and somewhat forgiving if you don’t hit the notes right on. The 30″ scale lets you to roll into notes with a slight twist or roll of the fingers. The neck has a between-C-and-U shape that feels good and is quite comfortable to play. A little more contour on the top of the body would eliminate our only nit; after putting in a few hours, the top edge of body started to tenderize our forearm. But any luthier will tell you how hard it is to bind a body contour, so this is forgiveable.

During our test, we had the opportunity to use the Mouse in a recording session at a local studio. Plugged directly into the recording console and with minimal EQ, house engineer Dave Swenson said the Mouse was “…the best-sounding fretless bass I’ve ever recorded.”

With the combination of the flatwound LaBella strings and the 30″ scale, the Mouse produced the muddy tone of an upright bass.

We also plugged the bass into a 4×10″ Genz-Benz and a JBL 15″ EON powered PA cabinet. Through the EON, we got a full, open upright tone that had just the right mix of that rubber band “boing” and finger snap. The Genz-Benz had more of a mix of a traditional fretless bass tone and an upright tone with more mids that added definition to the harmonics.

If you’re looking for upright tone in an exotic, lightweight package, this is the ticket – and for the fraction of the price of a good upright bass.