Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Dean Edge 4 Solid Body Left-Handed Bass Guitar, Trans Black
Product description: The Dean Edge 4 Left-Handed Electric Bass Guitar has a comfortable double-cutaway basswood body, and a bolt-on maple neck with a standard 34" scale. A 24-fret rosewood neck has mother-of-pearl dot inlays. The Edge 4 is loaded with 2 powerful Dean Active Soap bar Pickups that deliver a wide range of user friendly tones. Controls include a pickup blend, bass, and treble with middle stops, and a master volume. Other features include Grover tuners, and black hardware.
Product feature: Basswood Body, Basswood Top, Bolt-On Neck, Rosewood Fingerboard, Black Hardware
Product brand: Dean Guitars
Target attributes: Guitar Type
Answer: attribute: guitar type
value: electric bass
source: product description
attribute: guitar type
value: bass
source: product description
attribute: guitar type
value: bass guitar
source: product title