The shofar blasts are kosher whether the sounds are “thick” or “thin.” All types of sound are acceptable.
Length of Each Sound
The tekiah (long sound) should be as long as the middle sound of that set, i.e., for the first set, it should be as long as a shevarim and teruah combined (about six seconds), for the second and third set, it should be as long as a shevarim or a teruah (approximately three seconds).
Each of the shevarim should last for approximately one second.
Breathing
One must take a breath in between each complete note.
One should not take a breath in the middle of a note (e.g., shevarim or teruah).
There is an argument as to whether or not one should breathe in between shevarim-teruah. The custom is to take a quick breath in between.
In a place that does not have a specific custom, it is better to do the shevarim-teruah in the first group of tekiot (before Musaf) without a breath in between (but with a small pause) and during the tekiot during Musaf with a quick breath in between.
Wrong Note
If one blew the wrong note, he may have to begin from the beginning of the series that he's in the middle of blowing (e.g. tekiah- shevarim-tekiah). The Ba’al Makri (the one who points to the correct note) should know the laws in this regard so he can instruct the Ba’al Tokei’a as to how to proceed.
If the Ba’al Tokei’a was unable to complete the shofar blasts and someone else came up to complete them, he need not make the brachot (blessings) again, provided that he heard them when they were recited beforehand.
