We're always being asked this question. The short answer is yes subject to caveats. Here are some of the things that need to be considered;
Weather - Obviously this is a key factor. A string quartet will not be able to play outside in rain or if there is the threat of rain. Cold affects how our fingers operate so if it's too cold we cannot play outside. If it's too windy our stands and music will be all over the place and finally it it's too sunny and hot we cannot play outside unless we have some form of shelter.
Damage to instruments - String instruments damage very easily and as our instruments costs many thousands of pounds they need to be looked after. Clearly, damp conditions will affect the instruments but also as damaging is direct sunlight. Most stringed instruments are held together by glue. Direct sunlight will heat the wood of the instruments causing it to crack and the glue can loosen in the heat causing the instruments (worse case scenario) to literally fall apart.
Sound quality - Acoustic instruments sound great in good sized plain lightly furnished rooms because the sound produced is amplified for us by the room. We love playing in wedding barns for this reason. Outside however the sound that an acoustic quartet makes will simply dissipate in to the atmosphere. So if we have just done a wedding for you indoors then move outdoors do expect the string quartet to have a much thinner sound.
Solution - We need to work closely with clients to understand what is wanted so that jointly we can overcome the problem of playing outside and provide the best solution. The venue can also often help by providing sun umbrellas gazebos etc but if all else fails last year we invested in our own gazebo.